Existing charges. But it's hard to imagine Patreon would intentionally triple their service fee costs to themselves by charging pledges individually instead of in aggregate. The only thing that's changing is the service fees they're charging users.
It's not hard to imagine if you've ever looked at running a marketplace. ;) The one reason I'm not throwing stones yet is that the laws around money transmission are state-level and very weird and there's the possibility that they're trying to avoid getting slammed by then. Also, Stripe might have a beef with their bundling, too.
When I contacted them back in April when they were doing this, they mentioned changing over to billing monthly based upon when you first started backing a creator.
So instead of being charged once at the beginning/end of the month, you would instead be charged on the monthly anniversary of when you started backing someone.
I'm not sure they're (thinking about) switching over to this (yet), but I've seen mention of this in comments online, so, could be.
EDIT: They are:
> To do that, we need to move our payments system to treat your pledges like any other subscription service. In other words, we need a system that charges patrons at the time of their initial pledge, and on the anniversary of their pledge each month thereafter.
