No change to the configuration value so far as I can see - it's max 1 per hour (which is what you're observing).
Note that the posts eligible for bumping are those scoring >= 0 that have gone at least 30 days with no activity, have at least one non-deleted answer scoring 0 and none scoring more than that, and no accepted answer (also, they can't be lockeddeleted or closed).
There's a pretty reasonable chance that you just didn't have very many questions meeting those criteria until today...