I agree these are good questions/concerns to raise, but I don't think the InterSystems example is the most pertinent one toward some of the critiques implicit in those good questions. Their Kendall building just got bought out for some exorbitant sum ($825million) and they're not carrying out this move to reduce space or downsize. And I doubt someone is paying $825m for a building and not planning to keep it highly utilized. These details are all upthread somewhere. Probably just a biotech takeover of their old space, so they are shifting to a space more conducive to pure office. If anything this might point to the fact that not all office-lab conversion corresponds with deletion of office demand; rather a portion that office demand endures or grows despite it and needs to find new office space to support itself.
EDIT: actually, according to
this post, this move is an expansion of leased space from InterSystems. Their entire previous building, which they did not occupy all of, was 409,000 sq ft in total. Tough to know whether it's just a slight expansion or something more substantive, but it definitely appears to be on the additive rather than subtractive side in terms of impact on the office market.