“If...”
Now you have your answer. They didn’t stop them. You knew it too.
This report does nothing more than make the writer out to be an idiot, a willing dupe, a liar, or a paid disinformation specialist.
I don’t read any of this stuff any more. I am certain that absolutely NONE of it can be truthful.
By their own whining account, ‘journalists’ have said/are saying they have been shut out of the border areas and they have no access to individuals who come here or to the personnel who ‘process’ them.
What does that leave, but LIES.... RUMOR... DISINFORMATION, PROPAGANDA... what ever you want to call it... but NOT the truth!
Even beyond that, Mexico recently signed a diplomatic agreement with Guatemala to issue transit documents and facilitate Guatemalans transit across Mexico to the US.