Not sure what the rules are for EQ2 character data preservation,
but back in EQ1 they had a clause in the user agreement that they can only guarantee keeping character data for 3 months.
This does not mean that they will automatically delete the character data after 3 months. They will only do this if they are running out of space on the character database. So in theory, the character data stays there indefinitely until there is a need to purge the database.
I once cancelled my second account in EQ1 and decided to reactivate after 8 months, my character and all his gear was still there. But this was way back in 2001 and servers were probably not as saturated as they are now.