Earlier quoted context omitted.
That's not a remote problem, that's a project management and communications problem. Physical proximity is no replacement for clearly communicated requirements/bug reports/product roadmaps as well as tribal knowledge (which should not be tribal but documented somewhere searchable and robustly accessible), but it makes a nice hack when everyone is required to be in the office.
Agreed on it being PM/Communications problems. Definitely easier in the office though. Another thing is that it's often harder to write your question/problem in text as a message, when in verbal communication it's a lot easier (personally, YMMV). But having to organise calls to get that verbal communication is a pain.
A lot of folks are used to being lazy intra communications in an org, and imho, that shouldn't be an excuse to dissuade remote work when the benefits are incredibly clear. If you suck at comms or management in a more flexible work arrangement environment (which is okay! to get better at something you must first suck at it), it's time to get better.