Perhaps they'll add the Wt to Mauville seeing how it they removed gambling thanks to the Eu. By the way Emerald's Mossdeep had the wireless game place iirc as well. Perhaps they'll put the Extralink on the Mossdeep island.
The Entralink is to Black and White as the Bug Catchin Contrest was to Gold/Silver/Heart Gold/Soul Silver, or the Under Ground was to Diamond/Pearl/Platinum.
The Remakes would only cater to what the original games had, so the highlights should be Secret Bases(if they return), Contest Halls(if they don't just stick it in Lillycove or remove it altogether).
All of the other Specials were exclusive to the other games so I wouldn't expect to see those kinda mechanics in the remakes. Very little chance that the remakes would get Dream World capabilities as well seeing as B/W didn't get Pokewalker link ability.
Other than Contests and Secret Bases...oh and the Trick House, Hoenn didn't have a specific Gimmicked location special to it. (Two of which carried on into the next Generation)