Can Parents travel during this time if they have valid visitor visa after this Travel ban in effect

Hi,

I am trying to figure out if the current travel ban applies to the parents who have a valid visitor visa but could not figure out the proper information on that. I am planning on my parents and my in-laws’ travel during this time but not sure if I buy their ticket and they get denied entry for some reason. Can someone please help me understand the current situation around the entry of parents with a valid visitor visa?

Regards

Travel through Mexico with 14 day quarantine.