That was fake news actually.
Jones never said he would fire players for not standing up for the National Anthem.
Doug Baldwin claimed that Jones had said this - but Baldwin was referring to a facebook post that had a fake quote. Or more correctly had a bit of a fantasy story describing Jerry Jones in the locker room talking to the team.
Jones has said he finds the protests disappointing, but stopped short of saying he would fire anyone.
“Jones has said he finds the protests disappointing, but stopped short of saying he would fire anyone”
In other words, his real concern is lining his coffers with money and wouldn’t dare kill the golden goose, no matter how disrespectful or evil it becomes. Just like I’d expect him to react.