We are all told it does, but all the evidence is that it doesn't. It does also depend on who you migrate to.
The only time it matters is if you have an incorrect setting now, and hope it will be corrected by a migration. In which case forget it. Nothing will change that you will notice.
The full story is that two things, the MTR and FTR may indeed be reset. If you are suffering from a lower speed than you used to have and are moving because of that, then that would be bad news.
So tell us why you are asking the question, the ISP you are with, and what exchange you are on, and we may be able to give a more helpful answer.
Have a read of my
10-day training page for a bit more detail.
My broadband basic info/help site - www.robertos.me.uk
My domains,website and mail hosting - Tsohost.
Internet connection - O2 Standard.