Hiya,
just saw this, sorry for the late reply. Thanks for putting it in as a feature request. Regarding this:
This is very much an “internal logic” solution. From a users perspective, the action is broadly the same thing, ultimately semantics. Whether you have a group, turn it into a symbol and move it to the symbols page, or create an artboard and do the same thing, you’re still left with an instance of an symbol containing an artboard where you created it. It just feels like a needless wrinkle and as much as it isn’t technically a big deal, I guess my motivation for pointing these kind of things out is that I see Sketch as Figma, but with polish. I’d love to see you guys double down on refinement requests like these. (Not this one specifically, but you know what I mean)
Sorry, did not address your second point:
If there are dependencies on an artboard, graceful degradation should be considered. If it’s a link in a simple artboard-to-artboard prototype, it should just swap out, if chid groups and objects within the artboard have additional prototype links then simply notifying the user “Do you really want to do this? It’ll break X,Y,Z” - totally imperfect, but I’d take a warning over an arbitrary dead end. It’s something I’d want to at least test with users (Both new and old) as a hypothetical. Again, I’m not losing too much sleep about this specific issue, it’s more the inconsistency and the fact it’s not something you can really document you know? Something a user just has to know.