And how exactly does that fix the issue with the client going against the spirit (if not the law) of the GPL?

And that’s what I’m questioning. Would you? Would you think others here would? I wouldn’t. I’d rather go to whatever fork Fediverse devs favor instead. If anything, all the fear being expressed every time Threads integration is brought up only emphasizes that this is not how it would play out

The network effect can be strong. Say you’re now able to contact all your friends via your favourite Activitypub instance, you had to previously use Facebook.com or Threads or whatever but now they’re all here. You delete your Facebook and keep your Activitypub account to speak to all your friends who are on Threads.

Now Meta pulls the federation plug, or adds some feature that makes your Activitypub server not able to fully cooperate (Maybe you can talk, but you can’t video call anymore, or you can’t post GIF/images, whatever). Now what? All your friends are over there and getting annoyed with you. So… you eventually succumb and fire up a Threads account.

I guess I’m misunderstanding here - I thought Whatsapp would be the “service” in my case, I’m just making a client to hook into their, presumably open [to people who agree to whatever their terms are] API. So it’s more of a federation thing between services?

So I [in theory, I don’t know how to start with this on a technical level] could make a third-party Signal-compatible app, but allow it to connect to Whatsapp instead of Signal? Even if I can’t use my Signal account to contact Whatsapp people, that’s still potentially useful. Although I imagine the terms I’d have to agree to to do so would be full of nonsense that stops this being remotely feasible.