Eh, I doubt many people are burning their own Blu-ray discs - this does not apply to discs you buy that already have films on, those are manufactured differently, and are still being made.
But even if you do archive your personal data onto Blu-ray discs, there are still other manufacturers besides Sony.
This really isn’t a big deal.
Really though, who burns Blu rays. Yes I’m sure there’s a handful of people out there doing it but I don’t know anyone who’s still burning discs in 2024. Storage space is large and cheap now and way less hassle than discs. Companies as big as Sony can’t keep producing products for a tiny market it just doesn’t make sense.
What does a movie company not producing movies on discs have to do with ending production of rewrite-able discs?