It has been an issue before. Last summer, there were issues too. IMO, it is always a case of "buyer beware," and so for me, the same rules apply, "don't commit to what you aren't willing to lose." You can read old swap threads, see who is always on time both as hostesses and just as participants and who is not. But that is not always a guarantee, sometimes emergencies happen, sometimes a bad stretch clears up, and people get speedier. Last year, it got bad enough that people were talking about having backup hostesses, in case something happened.
With the usual hostesses, you can count on them to all back each other up. Plus, there are other swappers you can count on to have a hostesses back. Like if Kat ever gets into trouble, I can go over there and pick things up and make sure they get where they need to. But with a new hostess, without an established swap record, or a record of being tardy, the ground gets less stable.