I'm not so sure cooldown would be effective. Someone still has to override the cooldown to install the (potentially) questionable releases and discover problems. If no one does, you've only delayed the problems by 3/7/10/14 days.

After thinking more while typing this:

I think I'd agree we should indeed have a 10-day cooldown (i.e. don't install anything released in the last ten days.) I suppose I just don't think anyone should expect it to be the only mitigation.