Pre-scheduling is ONE way of getting people in sync, but not the only way.

For me and my team, there is a LOT of ad-hoc communication, preferrably in public slack channels, which leads to extremely productive conversations.

Furthermore, these are SEARCHABLE, which is a godsend; if an issue comes up once, it's very likely to come up again.

And, of course, there are times when we just jump on a zoom call quickly to review something that may be quicker than a bunch of slack back-and-forth.

There has never been a time where I felt "damn, it would be easier if I were there in person". If anything, in-person communication has always been hampered by the very need for co-location (including arranging meeting rooms or whiteboard, etc), and it's always been difficult to view someone else's screen unless they connect to a projector or large TV, whereas zoom has made pair-and -group programming almost inevitable.

I understand the social side of people wanting to be co-located, but from a pure productivity perspective, my team has been significantly more productive since WFH.