@Rectro @Raischub
Sorry, I made a typo. The answer was meant to read "pre-R21-licenses". I specifically asked MAXON if I would be loosing the R21 perpetual license and they said "yes, the perpetual license will be removed and you will get a new R21 license as a subscription license, and yes, you would still be allowed to use any older perpetual license you own ( = everything up to R20)."