An Evil Within/Bloodborne DLC crossover would be cool. Never happen, but it would be.
I'm tempted to pick up a PS4, but I know that we'll get a Bloodborne GOTY edition down the line. I'm old. Too old to wait for things. But I'm also broke.
Just get it on PS5 when the 'Remastered' edition comes out. In fact that's safe to say on any PS4 or XO title the way things are going.