thats impersonation of an employee or otherwise representative of the entity, and would be ultimately not be Microsoft's issue, but that of the person doing the impersonation.

Since they aren't employed by Microsoft, they can't substantiate or make such claims with legal footing.

I'm sure there are other nuances too that must be considered, however on the face of it, if a Chatbot is authorized for sales and/or discussion of price, and makes a sales claim of this type (forced or not) then its acting in reasonable capacity, and should be considered binding