I am not suggesting that a massive overbuild is a good ides, but I would think the Seaport is a great cautionary tale for erring on the side of slightly more infrastructure than you think you need, rather than less. We don't really know the transit demand profile of what Harvard and commercial interests are going to build out in this area. You don't get a second chance to put in the transit infrastructure without a lot of pain and suffering (and dislocation). The early stage build out will be cheaper than trying to fix a ghastly under-build mistake in the future.It's too much of a time chew to loop the 66/T66 and 64 there the way the proposed street grid is laid out. Chances are that's not going to happen...especially not with the proposed T66 because of the time sensitivity of its load-bearing route.
The gigantic busways depicted at West in the renders are designed with the hope that intercity coach buses on the Pike en route to South Station will pit-stop a mere 3 miles out for campus access. Which is probably also a faulty assumption, since there's excellent transit access from South Station to Allston for students and pretty small margins involved for the bus companies at even attempting the pit-stop.
I think at the end of the day you're looking at just campus shuttle buses there, which doesn't require much bus infrastructure. Malvern's indeed probably sufficient for that lone BU shuttle bus, if BU even bothers to run a shuttle bus to what's going to be an all-Harvard property. What we'll have to see is whether the gigantic busways in the West render get VE'd down, because right now there's a LARGE discrepancy between projected bus capacity (too much by a lot) and projected bus utilization (or lackthereof).