Well, obviously, you should be looking at M1's going forward since that WILL BE all Macs in the near future. Thats a known. Of course, if you don't HAVE to upgrade right now, delaying will give you the best possible chance to have all of your 3rd party plugins working with the silicon machines. Or, at least, the best possible picture of what things look like when it's time to upgrade.
But literally everything that I bought for my windows machine at the end of last year (NI, fabfilter, SSL, Waves, etc) are now working on my M1 machine. And working REALLY REALLY well.
Tom