"if they signed the dicharge petition, they would naturally be expected to vote for the legislation."
But like the sudden reversal of fortune that happened after the discharge petition for release of the Epstein files occurred, where 218 originally signed, and out of nowhere, a fusillade of Republicans joined with their support along with 45, then you never know how it will go until it goes...
H.R.4405 - Epstein Files Transparency Act
That passed 427 - 1 in the House AFTER a 7 week STALL by MAGat Mike swearing in the member who would be signature #218, and passed by "unanimous consent" in the Senate.
It could be a similar situation as what often happens in the Senate with "cloture", where GOP members will vote for cloture to allow debate to commence and will then vote against final passage.
If they can find a way to "spin" something in what they believe will be "their favor", then they will hypocritically switch to a "different side" at any point. 