To be honest I never found the representation of traditional Mexican clothing as offensive in any way (and yeah I live in Mexico).
It's just a way people can pinpoint what place in the World they are referencing.
It is not racist, it's just one of th ethings Mexico is known for, it's traditions and folklore.
And the hat, poncho and other stuff is traditional Mexico without a doubt.
Even people like Mariachis and such tend to dress up in traditional Mexican outfits to perform, and I don't see anyone mentioning they are being racist for dressing up like that.
Is it racist?
No because they are not making any kind of harmful joke about Mexicans in any way.
It's just fucking clothes goddamnit.
If Mexicans are okay with it, the rest of the world should just STFU, tyvm.