I was wondering about this as well. Notice they don't disclose what the cap is. Technically, a quest isn't complete until you click the button *after* the duration has expired. So I'm guessing this new limit will have some people sitting there with zero duration quests that they can't complete, and claim the reward, until the next cycle. As of now, it's impossible to complete more than 10 quests in the current 12 hour cycle without using DBC to auto-complete quests. Even if you completed 5 quests at the very start of a new cycle, and also start 5x6hr quests immediately thereafter, you won't be able to get a 3rd round of 5 in before the next 12 hr cycle refreshes your quest offerings. So if the new limit is higher than 10, they're doing it specifically to stop people buying their way through.