The way you setup your Addon, you don't have to worry too much.
If a user uses your addon ,he has been warned that his SavedVars should be backup'ed.
For People with Multiple Accounts it might actually be counter productive to use it,since at the moment
all Characters of multiple accounts will be stored in the same space.
Once it's patched, that won't work anymore, so they will not see all their characters on multiple accounts in the same Addon anymore