If its not going to pass, I imagine they will just postpone or call off the vote? Why even bother bringing it up if they're not sure it will pass. Isn't that what the whips are for??
Ryan has previously stated a belief that when house members actually have to vote on this on the floor, and a vote against means keeping ObamaCare at least another few months, that their opposition will suddenly melt away due to their hatred of ObamaCare, and they will vote yes despite previous no pledges. It's time for him to put his belief to the test.