Yes, but most from Europe and Asia. Consider that TG (the flag carrier for Thailand) flies to many European/Asian cities nonstop, but could not sustain nonstop service to ANY USA destination- their current USA service to LAX is not nonstop (hasn't been for a while), and their JFK service flopped. If there's latent demand from the United States to Thailand, why hasn't TG been able to take advantage of it?

Thailand is to Europe what Hawaii is to the USA- a warm weather tourist vacation spot, with SOME business travel, but lots of tourist travel. This is why you see things like TG selling their C as premium economy in Scandinavia (and why UA's 777 Hawaii config is lame compared to their 777 TATL/TPAC config). Tourists buying their tickets 6 months in advance aren't going to give you the kind of juicy fares a last-minute business traveler on NYC-LON can give you. BKK sure isn't SIN or HKG.

UA and DL are de-emphasizing their NRT fifth freedom operations, but UA has multiple partners at major hubs who can give their customers service to BKK out of NRT or elsewhere in Asia: NH as a JV partner, TG, SQ and OZ as alliance partners. DL... not so much (KE is hardly a partner at this point). So it makes sense for them to still run NRT-BKK at the moment, and UA to dump it, to concentrate on USA-Asia nonstops.