Independent but still wants to partner with MS.
To pay bills they'll need publishers to fund future projects.
So better to don't burn bridges, because maybe in the future MS could want to make a new Spyro or Crash and won't ask 343 or ID Software to make it.
But don't expect them to work in any game from MS soon, if they left and MS allowed them to go pretty likely is because MS didn't have short/mid term plans for them and the only alternative was to shut them down.
Microsoft should sell Crash and Spyro back to Sony, Insomniac and Naughty Dog were the creators behind it
When compared to Sony and Nintendo, MS had a weak banner of 1st party IPs.
So MS bought a lot of empty shells mostly because had brands that even nowadays are mostly dead, were popular in the past and still have vale to put them in a banner of IPs owned.
Other than that, specially having let Toys for Bob go, pretty likely they don't have any plans for Spyro and Crash at least for many years. But I assume MS will want to keep these IPs just because of the 'owned IPs' banner.
Regarding Sony, to acquire these IPs wouldn't generate them enough money because unlike in the PS1 days they aren't big sellers. And even if they make crossover games wouldn't match with most of their current IPs.
On top of that, Sony already has a ton of classic Sony IPs in the closet waiting to maybe be ressurrected, and a lot of super popular ones. They aren't short of IPs, so no need to buy.
Personal nostalgia of some boss is the only reason could make Sony buy them, but would be had to justify it as a business so other higher ups probably wouldn't approve it.