May I ask if these APIs are supposed to be public, or have you reverse-engineered them?
That may be the core of the issues - if these APIs are not supposed to be public, FD could save a lot of hassle by defining a public API and keeping it consistent (or at least warn people if they change it). They could even protect their own interests much better by providing a public API and covering it with NDAs.
That said - yes, the timing of this strike is painful. But that's the point. If this strike were to be done on a Thursday afternoon, nobody would notice.
As for holding devs to ransom - don't think so. If FD has a halfway regular setup, the devs won't even notice this. It's the executive level who should notice that and react on it. It's also the executive's job to
keep distractions like these away from the devs so they can do their job.
So DOBE Braben, Zac etc. should react on this. This is ultimately part of the company policy. Of course it
could backfire - but sometimes, you just have to take risks. And judging from the timing and the basically unamious support of the (major) 3rd party sites, I'd guess these developers are now
really fed up.
If this hurts Drew, he has my sympathy. But if he designed that event relying on the availability of these 3rd party tools without coordinating with those sites, that sympathy becomes rather limited. If the event (whatever that might be) can go on without these sites, all the better. In any case, it is still a level playing field for all involved - just maybe the level has shifted.