Whoever you spoke to is very uninformed.
Disney used to have E-ticket nights at the Magic Kingdom. If you were staying onsite you could purchase a ticket for $12 that allowed to access to the Magic Kingdom for 3 extra hours past closing. This was also limited as they only so many tickets. This wasn't every night.
NOW, if you are staying onsite at a Disney resort, you can stay an extra 2 hours (I think or 3) at certain parks at certain days. This includes ALL parks. You can also enter certain parks on certain days 1 hour prior to opening.