The Order 1886 is RAD's 1st new IP, if the game does well then I think Sony would be open to purchasing RAD, it all depends on whether they would want to be purchased.
Personally I think if it's mutually desired then they should go for it, same applies to other studios like Quantic Dream.
I would have thought Insomniac would have been a studio that Sony would like to acquire, but I guess Insomniac wants to remain privately owned.
I'd like for Sony to buy some indie studios and maybe merge them with the likes of Pixel Opus, to create a larger studio.