No... I mean I haven't seen any cases of someone who had a "greyed out" legacy account that they were unable to send funds from, that disappeared after they updated their firmware and/or reset their device etc.
[/quote]

Trezor is open source right? So if someone wanted to they could inspect the source code to figure out under what conditions a legacy account will become "greyed out". then we could know what was really going on. Should be a very simple matter.