isn't DSLR pretty much dominated by Canon and Nikon now days. Make sense Sony doesn't want to do it any more.
I expect they'll slowly stop releasing new DSLRs over the coming years.
And FWIW, a good friend of mine is a pro photographer and said he'll likely not buy any new DSLR bodies. But, he's still a few years away from needing a new body. Not to mention has north of $30k in glass, so would still run an RF with adapter for quite some time.
Most Sony users knew the Axx series (SLR/SLT) were dead when the A7 (mirrorless) released. Sony basically abandoned everything else to focus on their mirrorless platform and it gave them a huge market presence.