There’s good authentic and bad authentic.
I would call this “upscale modern Thai”. There are lots of new restaurants opening in CM all trying to serve creative Thai food. I think that’s partially because if you want a traditional version of a Thai dish, it’s not hard to get it for 40-80 baht (1GBP=43THB). If a restaurant wants to charge more, they have to justify it. My new favorite restaurants in CM are now doing exactly that, with updated versions of standard Thai dishes. I’ll be on the lookout for a lamb laab to go with the “pork rib in a red wine sauce with Thai spices”, the Massaman lamb, and the lobster khao soi.
