I’d like to think this is just an elaborate prank that got out of hand. One of the researchers got bored, checked the list of upcoming arrivals and recognized the name of someone who was really into linguistics but had a reputation for being gullible. A couple drinks later, the rest of the nerds out there were on board with the plan to gradually shift their pronunciation of certain words but never acknowledge the change.
Time passes, the not-so-cunning-linguist arrives and almost immediately begins excitedly taking notes. Before they can do the big reveal, this guy publishes a paper on the findings and everybody has to maintain the ruse since they’d feel bad about damaging the reputations of those involved.