TFOR 2:
I have been "lost" when X controller forgets to hand me off and eventually I fly out of radio range. After some screwing around I find the freq for Y controller and they either want to know what took me so long or who the hell I am
So........if you wanted to vanish, a freq change is a good place to do it
BTW - For *some* routes, there are sections that have no comms at certain altitudes. New Orleans to Tampa has one such area at 12,000 and below that is about 100 miles long. I do not believe this route is one of these.