To be honest, I hope they aren't switched over.

It gives people a reason to continue to collect / sell the favor mats.
And going by the fact that Aquapolis drops a ton of them, and that the items necessary to do favors have dropped considerably, I have a feeling that off hands will stay red scrips for a while.

Instead of spending the red scrips on off-hands, it's faster (and profitable) to make them and sell them on MB.

Aside from making off-hand's, it seems like there is little use for favor mats.
(Unless you want to make your own blue scrip equivalent gear for overmelding.)

EDIT: But to answer the question, I didn't see anything about this mentioned in the patch notes.