when can it be bad?
If you use apps, you can't even relogin. Expect this if you're using app like boost, sync etc. However you are okay if you're using Voyager because it is browser-based.
I've been having these issues at lemmy.sdf.org when they update to 0.19, for about two weeks now I think. I use Sync and the dev are aware of the issue. But there's still no fix even though the dev is very quick in fixing bugs before. So I think, this is a major issue for app and it will take quite a while before we will see any fix.
Yes, true. they might be in the middle of updating the server of something. Usually it should be okay. That's my main instance by the way.
Anyway why do I suggest it? SDF has a long history of maintaining public access Unix usenet/bbs server, since the 80's. So they have a long track record of maintaining public server. For them to simply abandoning server hosted by them would be unheard of.
They also have diverge userbase, liberal and geeky. I simply can't imagine any lemmy instance will defederate from them. That will be brazen, simply say.