Dane's son is about five years old and the film takes place in 1989 meaning Jordan was born in 1984 the year Michael Jordan turned pro. It wasn't until Jordan had been in the league a few years and established himself as a superstar that people started naming their kids after him.
Of course, the name could have nothing to do with the famous basketball player. But, it seems like it was intended to be that way.
Having done a little research I found that in 1984 Jordan ranked 85th in popularity of boys names in Texas with 329 boys being given that name in that year.
Note, that by 1989 it had raised in popularity to 53rd with 642 boys being given the name.
That doesn't necessarily mean that there should be no Jordans named before that time. In 1993 I knew a Jordan in Texas who was about 25 years old, meaning he would have been born and named in 1968!
Jordan has always been a name . . . popularity doesn't have much to do with it. As long as a name is old enough and not just brand new/made up by a celebrity, people still get given names for all kinds of reasons, not just because of a celebrity.