Very likely! As I stated on X and Discord, I'm sending the rewards retroactively to everyone who did fanart in the last... roughly two weeks! Basically everyone who posted one after the release of Update 11 on Patreon and whose fanart is now queued to be featured in the credits of the upcoming Update 12 will still get the rewards retroactively!
I'm just taking the time to reach out to everyone to give it to them!
And, of course, every new piece from now on is eligible as well :D