They aren't even BoPs they're called Warbirds now. a Warbird is a type of heavy cruiser. A BoP is a light escort/heavy scout ship. I'm not sure why the category and type of ships have been mixed and mashed. Also haven't seen either a Romulan science ship, nor a Romulan scout ship in STO yet.
Warbird is now its own unique type of ship, with some that lean towards escort, science and cruiser roles, at least according to this:
Q: (felderburg) Will basic Romulan ships have the three standard variant, escort, cruiser, science?
Dstahl: Romulans have their own unique ship class, Warbirds, which is the first new ship class in STO. This new class uses singularity cores instead of warp cores and introduces new ship combat powers tied to the harnessed energy released by the singularity core.
Max-level Romulan Republic captains will find a nice variety of Warbirds that each gravitate towards a specific type of existing ship class and play style. There will be some Warbirds that lean towards existing classes (escort, cruiser, science, etc.) that players are familiar with, though they will all feel distinct in that they are from the new Warbird class.