So, if for example, i work for a studio, on a sequel to a game that already has a healthy speedrunning community, that is already hosted here on Speedrun.com

How would i proceed to request the addition of the Game and Category on behalf of the Studio without submitting a run?

It would be cool to drop the game + category on the day early access opens up.

In some cases submitting a game request for a game that hasn't been fully/at all released will still be permitted a leaderboard, especially when other games in the same series or development cycle are already on the site. You can submit a game request as normal and attach the proper context as to when it'll be released and why you can't have a run of it yet, or in the case that the game already has a series page on the site, you can have the series moderators add a board which can stay dormant until the game releases.

Generally the creator(s) of a game don't request the leaderboard. The person who requests the leaderboard should be someone who intends to maintain the leaderboard for the game indefinitely. In this case, it would be appropriate for someone from the community for the first game (ideally one of the moderators) to request the sequel. They can do that no more than 3 weeks before the game releases.

Thank you very much for the replies, i will run it with our planners and get into contact with our speedrun community to add the sequel to the boards so that the community itself can maintain it as i cannot guarantee someone would maintain it forever on our side.

Thanks again!