No, CX does not "help" any nationals "get" US Visas.
CX is in the airline business, not in the immigration business.
The Canadian/US visa issue was an expeditious means of continuing to do business without a major upset. There were a load of Canadians living in the US under the terms of a previous basings agreement (not well thought through) and all that CX has done is to facilitate US work visas for them whilst in the employ of CX or a subsidiary.