Nope, they’re two different distros. The reason that Raspberry Pi OS was renamed is that the 64 bit version does not use code from the Rasbian project.
And all Linux distros are basically the same thing, you can pen test with any distro. The package managers and repos are what makes them unique and interesting.
I really have no idea why someone would make another pen testing distro. Kali was enough, Parrot was like reinventing the wheel. I mean any descent distro has those same tools in repo. Install them if you like, make an image of the install, use it as a pen testing distro.