Honestly if anything it would probably lessen ticket sales so people can save up for PSL's and season tickets. My guess is it's the same amount coming from LA as usual.
In terms of San Diego, I always felt it was a military town (Navy and Marines have a big presence there) so there's always going to be a solid fanbase for the away teams from all the different backgrounds in the area.
Most people don't want to make that drive (from LA or San Diego) and them potentially moving is pretty unlikely to change that. The drive is downright miserable.
Two of them would be for me if they weren't bracketing Thanksgiving with two away games.
I'm going back there for the holidays to visit my girlfriend's family.
Last year I was there and they were in Tampa. This year I'll be there and they'll be in Cincinnati, I swear I'm going to be pissed if they move to LA next year when I'm moving to St Louis.
I'm not convinced that the football gods aren't just keeping them from me. If I stay in LA they'll probably stay in St Louis.