It is my understanding that email notifications for new posts are delayed by 5 minutes (or whatever your grace editing period is set to) and I think this is an excellent feature which illustrates the attention to detail in the developer team (and community)
However, it looks like summary emails are not following this logic. When I just created a new topic, one of my test users received a summary email within 1-2 minutes and that email had my new post as its first (in fact: only) “Popular topic”.
I’m inclined to call this a bug, but maybe I’m taking the grace period feature too seriously? In any case, I think it would make sense to have summary emails ignore topics that are less than
editing grace period seconds old.