I haven’t seen the news release, but I would hope they are explaining those terms because they are going to have someone on to talk about github and they were planning on using said terms

AFAIK the current anticheat systems on Linux only run in userspace not at kernel level. This does mean Linux is theoretically easier to bypass compared to windows, some games just dont seem to want to take that risk. For as you said 3% of the market.

I personally disagree with that stance though, because all it takes is a hardware device and all software anticheats are useless no matter the os (think a raspberry pi, and capture card). So anticheat is really a losing battle anyways.