They would have to decide it is worth it to them. No one is forcing them, but Ron brings a lot to the table. I just think it is as Pres or not worth it, but the LP doesn't have to do it at all, of course. I can understand them wanting to stick to their procedure. However if they were planing to break procedure to make Ron VP, I think that simply isn't worth it and Ron should run independent or not at all in that case. The presidential debate is what would make it worth it, and Ron, not GJ, polls well enough for that to be a real chance.
BUT, the LP is its own party and can make up its own mind if it wants to move things around as much as it would have to to do that. I don't think anyone is saying the LP HAS to do anything.