Scanner compatible with M1 processor

Go to Canon's and Epson's (and another other brand you're interested in) websites and look for photo scanners that are AirPrint compatible and be able to scan the size of your work. They will be compatible with the new Macs.

If you're looking for a multi-function unit, i.e. printer and scanner in one, any unit listed in this Apple document will work: About AirPrint - Apple Support

The fact is it's not Apple's responsibility to provide a list of all of the third party devices that are compatible with the macOS. It's up to the developers of those devices to code proper drivers for their own devices or rely on Apple's APIs for compatibility. And if they choose not to provide updated and compatible drivers for their older hardware then it's on them. After all, they want to sell you a new scanner from time to time.

I suggest you take a look at the features of any particular scanner(s) that you are considering and check the mfg websites for compatibility assurances.