xbox hall of fame

hello, I have read the entire hall of fame pages and the terms attached to them and I'm still not clear on my answer.

My question is regarding the lifetime achievers and gamerscore and also the two shorter trials for gamerscore and achievements.

What exactly counts for these? In the lifetime achievers it makes it sound like everything counts since the 22nd of Nov 2013. In the shorter ones it reads as if only X1 achievements are counted if that's true does backwards compatible games count? Do Windows
10 games count or no?

Thanking you for your time.

:)