I'm confused as to what part of ....
... indicates to you that the policy ever force the renaming of level 50s?
These days having bunch of level 50's ... or even one for that matter ... doesn't mean what it once did.
Someone could have spent far more time with a level 30 character online that some with a level 50.
When it comes down to it, the population base is too small to force the renaming of any characters.
That being said, if you can't log in a character once a year, then you really don't care all that much about a character.
I have over 100 and I think the longest not logged in at this point is like 274 days, and I have the feeling like I have less than 10 that haven't been logged in more than 200 days.
Have you checked to see if any of your characters have been neutered or genericized?
I don't think this is a situation to cause a panic.