Following the rules, if you didn't change anything in the game, you totally can upload your game as WebGL. Even after the publication. But you need to do that on your game itch page's
Okay, I‘ll just do that, wanted to add an easter egg but i think I wont do that, thank you :)
Adding an easter eggs is not authorized. You can fix major bugs only (or create a build for another target)
I will just upload the same game as webgl