I think you should be fine. (Please note that I'm not a printer expert so maybe other people should weigh in.)
I just looked at the "official" Pixma Pro 10's specifications for Mac on the Canon site, and they are SUPER old OS..es ... 10.5-9? Not sure why Canon didn't future-proof the list of operating systems. For example, Windows 10 isn't on the list either, but I have to think that works as well. The Pro-10 has the same OS specs as my Pro-100, which works fine with the OS 10.14 that I'm running.
Also that's very exciting you found a Pro-10 in the wild! It's the model I was looking for but with the mass shortages that have been going on, I opted for the Pro-100.