I am positive that Reaper itself will not show any problems on that behalf.
The new M1 ("Apple silicon") Macs seem very interesting regarding performance / price and performance / power consumption ratio. Also Apple seems to promise a great future for that product line (M1X, M2, ....)
Hence (IMHO other than Intel Macs) this seems like a decent move.
Of course (AFAIK), Reaper does have a native M1 version (still beta right now) and no old project loading or licensing problems whatsoever.
OTOH, I feel that this might only be perfect, if all plugins used in the projects feature native (non-Rosetta) M1 (i.e. ARM CPU) versions. AFAIK, this is not yet really common in the industry.
E.g.:
No Native Instruments plugins are native ARM right now. They provide list of what products are compatible via Rosetta.
Kontakt is not mentioned there .
Moreover of course you need appropriate (e.g. approved MAC-M1) drivers for any hardware you use.
So I will wait some time before considering to buy new hardware.
-Michael