i plan to keep using watchkit for my watchos app, until they force min release of 7 (maybe in a few years, apple really hasnt moved the min target of watchos that much) then i will probably just drop support. No sense of trying to rewrite everything that doesnt get used to justify it anyways. Kinda stinks, but apple calls the shots. I
noticed even before Beta 3, if you created a new watchkit app, there was no option for storyboard, only swiftui, so not too surprising here, now they have a deprecation warning to kinda go hand in hand with that. so to your points my opinion:
Your app will continue to work just fine, even if you have a watchos target greater than 7.0. I dont see apple simply just removing watchkit support for watchos anytime soon, possibly never. Just new apps will have to be done in swiftui.
thats a good question, probably their desire to promote swiftui as much as possible
I dont believe so, i think deprecation is a strong word here, but going forward they want new apps (and maybe in some fantasy dreamland) existing apps to use swiftui.