Roadmap: EOL for R21 Plugins?

[dinf]

Hey there,

I just saw that one of the lastest versions (2023.1.3-[R4]) is up from R21 while one before (2023.1.3-[R2]) is up from.R15 to R2024.

This seen, my question is: is there already a plan, from wich date on R21 plugins will also be obsolete?
1 year, 2 maybe? Or more or less? This is an important and serious question, I think there are some C4D Users wich also stuck on R21.

Thanks alot!