If you want to make a character moveset, just find a thread it's appropriate in. Likewise, a moveset is not grounds for a new thread anyway, so the fact a character has a support thread means... you post your ideal moveset in it. That's simply contributing.
Just posting movesets is not contributing much at all. Support threads need actual plausible opening posts, which should be about who the character is, and what they can do. Far more than a moveset. At best, you'd be contributing greatly by posting a moveset in a support thread for a character you like. Then it can get critique and generate healthy discussion.
As for this thread, this isn't a place to rant. You don't obviously have to continue doing more movesets, but I'm sure those threads would appreciate more additions to their ideas anyway. I make lots of movesets myself, but due to how old they are, they need far more updating first. They're too simple. We encourage you to contribute, of course, But you should not feel obligated to post in a certain thread outside of specific circumstances(like if you created a forum game and you are running it, and even then, you should be having fun first. Players will understand if you need to take breaks).