I did some more research, and I think the new lounge is open! There is Pre-Flight Dining (like the one in JFK) for F and HON members. It's not quite as large as the 16,000 sq ft JFK lounge but doubles the old lounge size and comes in around 7,000 sq ft.
http://www.frequentbusinesstraveler....nge-in-boston/
corporate-wage-slave took this photo of the lounge listing sign over on the BA forum, and it shows that the new LH lounge is open (and on the 4th floor).
Videos of new lounge dedication: