Mark -- It appears that Y!G is pulling the plug on even their "new, improved" email-only product, effective Dec 15 (one year after removing all online content). See https://en-global.help.yahoo.com/kb/SLN35505.html On that basis we are expecting a second wave of refugees, with the corresponding inquiries.
Are you still offering uploads of mboxrd message archives in return for a year of Premium (not the Premium trial)? Some folks still have their privacy dashboard downloads from last year, or may have a folder in an email client that can be exported into this format. It is understood that messages posted in the past year that were not so captured are irretrievably lost.
If so, what is the best way for such people to contact you? We in GMF need some way to refer them to someone who can do something about it.