I don’t mean to pick nits, but Raspbian/RaspiOS is not Debian-- just the same that Ubuntu is not Debian. The builds/repos are different and Raspbian has even gotten architecture naming screwed up (see: armhf on Raspbian is not the same thing as armhf on Debian) … this has led to people trying to use Debian packages from Raspbian and finding out they don’t work.
I’m not sure about Raspi’s packaging of tor, but I know that Ubuntu’s repo has not been good about keeping up. In the case of Ubuntu it’s certainly better to use Tor Project’s repo until Ubuntu establishes a better track record of updating tor.
If the only intent for the rpi4 target is to run a bridge, Debian with Tor Project’s repo seems like the best bet. Unless there’s something drastically wrong with Debian on Raspberry Pis that I’m not aware of.