[Legislurker]

I would think so. GATS is not entirely the same as the tariff schedule part of the WTO, but my understanding is that
MFN still applies. Read the language of how GATS was written, its each country agreeing during the last "round" to open up sectors to trade. You could open or exempt, but everyone pretty much had to agree with everyone else's level of openess or closedness. For instance, the EU opted out of cross-border gaming, not US gaming, but all gaming.
The entire premise of the WTO was to thwart bilateral honey deals that excluded the world from trade, though customs unions like the EU and NAFTA and Mercosur have thwarted it some. Im sure its rife with exceptions, but only ones already negotiated. Remember everyone has to be placated before the recommittments are finalized as well. The EU wants concessions in industries it has an absolute advantage in like legal services, so they could care less if Indian lawyers can hang signs in the US. The EU will still benefit the most.

Antigua's scope for negotiation for a "deal" would be not related to the recommitments, but in telling the dispute settlement body the US complied. Say they struck a deal where a trial period for just the companies in Antigua were allowed to operate 3 years to assess the situation. I don't see that though I think Antigua floated it before. Then, conceivably the US would be in compliance, case closed, no recommitment penalties. But, they can't say no gaming, Antigua can now sell direct home insurance to everyone in the US with no corporate tax. That would violate the entire idea of what the WTO is about.