The MPs have been going a bit haywire lately, slightly more so than at the beginning. There's been talk of not recognising former USSR countries' independence because of some weird constitutional reasons too. Political threats don't mean direct action, especially when they're still having some struggles in Ukraine
I think the planning part of it for the audience is probably the main thing the EBU is working on. If the situation doesn't improve but half of Ukraine continues to remain relatively safe, Governments won't exactly recommend their citizens travelling and the airspace would need to be opened or you'd have even more people crossing land borders
Also, there could be issues with broadcasters disagreeing with a decision to host there too because they need to get their props across the borders, then their artists and whole delegations, presumably press (though that could be done online fairly easily) or at least commentators too