Presumably, the frequent flyer programs between Midwest and Frontier will be combining in the next several months (Oct 1?).

Assuming the company sets up some routine to automatically transfer Midwest Miles over to Frontier at a certain point in time, will future Midwest Miles postings be accepted by Midwest and get swept over to Frontier or will these postings be rejected because the Midwest account no longer is valid?

I'm specifically thinking of slow posting partners such as Live Search.