I do not believe this to be true.
I cannot find any supporting information to back it up.
I have printed with many dual and tri colour filaments on the A1 & A1 mini, not from Bambu, but, I cannot see their mix can be so difficult as to prohibit it use on the A series printer.
Yes, which is why the guide I provided is such a good tool. Locate the filament, and see what if any restrictions apply.
As new filaments are added, the guide is updated. No guesses are required.
Hardened Steel Nozzle Required? = YES