If an applicant decides to add another applicant to the loan midway int he process, wouldn't that require re-disclosure?

Yes - Borrower requested change

No, it doesn't REQUIRE redisclosure. It is a valid changed circumstance but what is it changing? It has no effect on the fees so why would you redisclose? The only time redisclosure is REQUIRED is to lock a rate.

Additonal credit report fees, possible changes in title or filing fees as well.

That's what I was thinking...there may be changes in fees (though small), but even more so, doesn't the new co-borrower have the same right to the time frames involved (per MDIA, etc.)?