The restrictions made by the Congress on those possessing Iranian nationality are only to the Visa Waiver Program (VWP).
Canada is not a participant in the Visa Waiver Program. Canadians entering the US on Canadian passports do not do so under the VWP.
I do not believe your parents will be affected by these changes.
http://canada.usembassy.gov/visas/information-for-canadians.html
Credit:stackoverflow.com‘
4 Mar, 2024
5 Mar, 2024
4 Mar, 2024