Not even. This is a functionally worthless routing - New Yorkers heading to Boston already have the Northeast Corridor service into South Station, everyone north of Haverhill heading to Boston already has the Downeaster into North Station, the track connection between Worcester and Ayer is perfectly serviceable for a once-a-day fun train land cruise and there's a path from Ayer to Haverhill and on through to New Hampshire.
Woburn and North Station lose direct service to New York City on the fun train, but Worcester gains it, the relative slowness of the direct trip on freight tracks from Worcester to Haverhill works out about even versus dragging this thing all the way downtown, the one reverse move you MIGHT need to make in Worcester (unnecessary if you build another platform at minimal expense) is going to be much less painful than the in-and-out you'd need to do at North Station would be simply because of how constrained North Station is, anyone in Boston or looking to get to somewhere in Boston is probably going to be riding the T at some point anyway and it makes no difference which terminal they come in at... the biggest and only real losers in routing the Downeaster to New York away from Boston are the North Shore park-and-ride set who will not be able to park at Woburn and get a single-seat ride to New York.
NNEPRA has already proposed a NYC-POR train on the Worcester-Ayer routing. Like...two months ago, proposed this. It will never happen.
1) This has already been timed on a RR.net thread, with corroboration, based on the maximum possible speed of every piece of track on the Ayer bypass if upgraded to its tippy-top potential. Grand Junction beats a full-speed Worcester-Ayer handily every time. EGE did the maths on this one. Sorry...it's slower by a margin wide enough that there's no tricks to pull to close the gap vs. a Grand Junction routing.
2) Massachusetts is a link in the state-sponsored chain required to run it. Under absolutely no circumstances will they allow an Inland Regional or Downeaster slot to skip Boston. No way, no how. Worcester + Lowell + Haverhill < Boston. If NNEPRA doesn't cooperate, the train doesn't get allowed in MBTA territory on the Fitchburg, Lowell, or Haverhill Lines which it must traverse. It vultures both an Inland Regionals slot and a Downeaster slot when congestion on the Western Route and congestion in Connecticut don't make those slots expendable. That's their self-interest, and that's the leverage they hold over any attempt to put the kibosh on a train that could be making a faster trip if it went to Boston. Do business on their turf or it doesn't happen, and there is no business to be done--or possibility of laundering it around them--without engaging a revenue source the state can tap in Boston. Again, NNEPRA already proposed this to cool reception.
3) Amtrak is not qualified on that route. It is on the 100% of that train's territory if it goes via the Grand Junction. Amtrak already is sick of NNEPRA's batty Crazy Transit Pitches for northern Maine and for losing focus when it should be doing all it can to shore up the badly underperforming Brunswick extension. No way, no how do they do crew qualifications in new territory for the fun train. It's too little revenue for NNEPRA "cut 'dem checks" to sway them. Again, they already proposed this like two months ago. Since then Amtrak has brought the pain on them reading NNEPRA the riot act over Brunswick and them getting caught flat-footed on customer service by all the track condition-related delays. Amtrak doesn't want to hear about service expansion Crazy Transit Pitches in frickin' Maine until those spazzes get their house in order.
4) Reverses at North Station are no issue. Pull in, lay over, pull out. Fitchburg and Lowell crossovers are immediately adjacent to each other, and to depart/arrive at tolerable times in NYC or Portland this is not going to coincide with peak rush hour when drawbridge congestion puts a mild premium on getting off the platforms quickly. Amtrak reverses every single day all day at 30th St. Philly in much more crowded environs for every Keystone train, and does the same at Springfield Union for every Springfield Regional, Springfield Shuttle, and Vermonter. It's a zero on impact because all their NEC crews are qualified to do it. T crews...yes, they'd be sluggish because it's not a regular practice to do on a 'live' revenue train. T crews aren't running this thing.
To the original point...yes, it's an insignificant zit of a route and nothing would be lost if it didn't run. Because there is treeeeeeemendously more upside in building the Urban Ring, and if they fix the subway's performance under load and up the frequencies on the railroad the transfers from Back Bay do make even time to North Station vs. a direct on the GJ even at its best speed. That's where Worcester loses nothing.
The literal only train where where a direct to NS is necessary and wouldn't work with a transfer is a NYC-Maine train where the weekenders hauling their luggage 300 miles is the linchpin of the train's entire demand. And Massachusetts' only in-state interest in allowing that is to be able to have it run as a de facto regular Inland slot that only makes a minor diversion to NS instead, and then turns into a de facto regular Downeaster slot. And it's because of frequencies; whether it's a 'fake' Inland + DE being run on somebody else's schedule, it's a slot serving a frequency for the same in-state demand. And that makes the tiny little tweak in the routing fully palatable (not to mention dead-minimal additional cost overhead). Slots on those less-frequent pair of Amtrak routes are way too valuable to pass up. It would run contrary to this state's entire reason for investing in the DE and the Inlands to give away a Boston slot they're not going to recover by other means. They will never allow that.
That's why not only is the slow route to Ayer not going to happen, if NNEPRA keeps obliviously proposing it they're going to get told by MassDOT--or possibly even the governor--"Boston, or GTFO because your train's not getting permission to enter northside dispatch territory without it. Nyah-nyah."