I thought the pit lounges were the hospitality suites over the pits, and so you would need an invite from whoever had the lounge for Le Mans, usually one of the teams or sponsors.
They are, just as you say. I think DB was confused as the French use the same word -
loge - for both the free-access balconies in Stand 34, and the hospitality boxes in the same complex, access to which is by invitation only.