Is there any (semi) official exlanation to generated OP levels

I'm not sure where you got the documentation from, but I understand that on worlds with level 80 max it is slightly different once you get to the higher levels. @EE_Elephterion posted about this somewhere, I think.

https://forums.ea.com/en/commandandconquer/discussion/256766/mechanics-of-spawning-camps-and-outposts/p2 is the relevant thread.

Some changes were made in 21.1 to accommodate the higher limits for level 80 worlds, investigations are taking place to see if they are effective. They worked on the PTE.