Maguuma portal and beta weekends
Simple and short. Do those who got the heart of Maguuma portal gain access to the beta weekends that the pre-order has?
If you got a portal, and can not see a beta slot on your account right now, chances are the answer to your question is no.
The beta access is based on the SKU associated with your account as far as I know, because when they removed beta flag from accounts they changed the SKU of all non-heroic edition owners to the heroic edition SKU at the time (there should be a dev response to that effect somewhere).
So unless they announce a new portal farm it seems quite unlikely, at least if the SKU used during the previous beta events is the same as base HoT edition currently.