I’m not sure this an act against religious faith or expression. I can pretty much guess (admittedly having done no research) that the ban on “celebratory gestures” came out of some taunting and showmanship by race winners as they approached the finish line, perhaps dancing, pointing, running backwards across the finish line or other such crap. Making judgment calls in this context is likely more dangerous than either letting it all go or prohibiting it all.
As long as the rules are clear before the race, and evenly applied, based upon what I have read so far, I support the decision.
I know about bans on “celebratory gestures” such as when scoring a touchdown for example. But just holding up a finger? Really, where do you draw the line? And it was specifically referred to as a “religious gesture”, not a celebratory one.