I don't think it's a complete invention - if you look at the previous winners of other awards,
Man of the year
2023 - none
2022 - Josh Cavallo
2021 - Billy Porter
2020 - Luke Evans
2019 - none
2018 - Edward Enninful
2017 - Nyle DiMarco
2016 - Wentworth Miller
2015 - Evan Davis
2014 - Tom Daley
2013 - John Grant
2012 - Charlie Condou
Woman of the year
2023 - Dylan Mulvaney
Person of the year
2019 - Sam Smith
From the looks of it, when they launched their awards in 2012 it was pretty much just a gay man awards thing, with people being picked based on their appeal to gay men (e.g. Marina and the Diamonds was the 2012 Attitude Music Award winner), and "Man Of The Year" just meant their favourite person or MVP or whatever. So when they pick people who aren't men for that year, they rename the award.
That's... maybe a bit more galling, though - the first ever "woman of the year" they picked was Dylan. Although maybe it's funny, because they've only ever crowned men, or men who insist on not being called men.