That's my bet too. They weren't hosting the site itself on GCP but they were using them for trust and safety services, and I bet that one of those services was anti scraping prevention with things like ip blocking and captchas, which would explain why scraping suddenly became a problem for them the day their contract ended. It can't be a coincidence.

Oh yeah I completely forgot about that particular idiocy, Elmo gets up to so much stupid shit that it's hard to keep track.

But I'd also be willing to bet money on this being somehow at least partially tied to ditching GC, likely due to not being able to pay (at that's what is implied by them refusing to pay the bill.) I guess Elmo thought "how hard can running some servers be? I'm a rokit skientist" and decided to just skip paying the bill as a power move instead of trying to make a deal with Google, and now the remaining developers, ops people etc. – those poor bastards – are paying the price.