In terms of Level-5 getting bought out by Ninty or Sony, I'd imagine it would more or less be a pick your poison type of deal...
If Sony bought Level-5 then that might make their prospect of ever getting any content in Smash go down the drain unless Sony pulls a Microsoft down the line, though on the other hand, they might have a better shot as reviving their co-owned stuff from Sony like Dark Cloud again, maybe.
On the other hand, if Ninty bought them, then they might get better marketing support for their IP's like they did during the DS/3DS era, which most of them are already heavily associated with Ninty as is and they'll prolly not get thrown in the dust as hard when it comes to Smash content as they did for Ultimate... On the other hand, their Sony co-owned stuff like Dark Cloud would probably be buried into an even deeper legal hole than it already is at this point...
I think the best buyer out of any would be Namco actually. They'd probably be able to retain most of their freedom with them I'd imagine.
But that's only in the absolute worst case scenario, overall, it may be for the best that they remained independent, especially since I'd imagine they don't want to repeat another Dark Cloud type of situation where they have little to no control over their creations.
