"Level 1 and above characters that have not been played since January 2017 will have their names removed.
Characters will have the opportunity to choose a new name upon the next login."
and
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Type: Posts; User: Obnoxious
"Level 1 and above characters that have not been played since January 2017 will have their names removed.
Characters will have the opportunity to choose a new name upon the next login."
and
...
As there's nothing against any rules about taking a name and simply not making extensive use the character with it, no, there's nothing to be done besides hoping they delete it or waiting for another...
So no, if you indeed had donated and your characters are missing, it wasn't because of the clean up.
The issue with certain Lordaeron characters having problem logging in is being checked:
EDIT: The issue should be fixed now.
Did you report that to the GMs, with proof? The inactivity clean up was meant to, as the name says, deal with inactive characters. It had nothing to do with characters that reach the minimum required...