surely 2021 GOTY is not "games that came out in 2021", but instead, "game of the year that has come out since the last GOTY"?
else if anyone releases a game in that window of after the awards and before year end, they can never get an award?
Possibly but wouldnt it just make logical sense for a GOTY to be in that year. Why not just make it Jan 1st to Dec 31st of the year in question. I mean Steam didnt even announce its winner (which was voted online by the players anyway) til after the 31st Dec. If every GOTY ran Jan 1st - Dec 31st, then you could easily have it as needing to be in that calendar year.
I dont know why Cyberpunk wasnt in the GOTY 2020 Steam Awards, Cyberpunk came out on the 10th Dec 2020. The Steam nominees werent decided until the 17th December and the voting ran from 22nd December to Jan 3rd. So Cyberpunk was definitely released before the 2020 Steam nominations and voting.