Residentes do Canadá, México ou Caribe são tratados de maneira diferente em relação às regras destinadas a contornar a concessão de visto para o Canadá, o México ou o Caribe.
If you are admitted to the United States under the VWP, you may take a short trip to Canada, Mexico, or a nearby island and generally be readmitted to the United States under the VWP for the remainder of the original 90 days granted upon your initial arrival in the United States. Therefore, the length of time of your total stay, including the short trip, must be 90 days or less. See the CBP website. Citizens of VWP countries who reside in Mexico, Canada, or a nearby island are generally exempted from the requirement to show onward travel to another country when entering the United States. Learn more on the CBP website.
Fonte: link
Mais importante ainda, as regras dizem respeito aos viajantes que fazem "viagens curtas" ao Canadá, México ou ilhas adjacentes; você não será um viajante assim.