I'm not sure if there will be a Bloodborne 2. The Souls Team and Miyazaki said they wanted to make a different type of game after DS3 separate from what they had been making for the past few years. Not to mention I can't fathom how to make a continuation from Bloodborne's plot, barring a soft reboot.

Oddly enough, I can see From Software getting a new team to make Dark Souls 4 before Bloodborne 2.