To be fair, the Somerville Community Path extension tied to GLX is eventually going to terminate here. And get connected to the Esplanade paths (hopefully with rebuilt ped overpass at Leverett Circle). So what greenspace they do have is going to be a pretty key node at tying together the urban trail system. It'll be a pretty nice spot when all the paths finally connect. I would agree, though, that token patches of grass ≠ useful greenspace. I hope the concept gets fleshed-out a lot more and justified on usefulness grounds at tying together the neighborhood and its connections.
As an aside, as great as those drawings look that's still not going to be a functionally knit neighborhood unless they tackle the elephant in the room: that gaping Route 28 chasm dividing the neighborhood. High-speed 6 lanes is going to be big isolating factor until O'Brien Hwy. gets busted down to 4 lanes with functional bike-striped shoulder, better sidewalks with less hair-raising proximity to traffic, and more inviting center medians to make crossing all those lanes a less daunting sprint. Plus restoration of the Leverett ped overpass and blowing up the McGrath monstrosity that feeds all that awful high-speed traffic out of Somerville. The state's been sort of implicit that that's all a goal. But if Northpoint and Phase I GLX (Lechmere relocation first) are really gonna happen soon, and reach their full potential, that general goal has to start evolving into detailed specifics. The deal to streetscape Lechmere Sq. isn't yet specific enough to traffic-calming Lechmere Sq.