I haven't seen evidence it would have any effect. Best evidence so far is that they try to cut bus service, as the single largest operational cost, as much as they can get away with politically, and then they sort the rest of the budget accordingly after that rather than start from 1.1% of revenue.

I think there is as much or less evidence that they'd raise train fares, reduce parking subsidies, raise or implement parking fees, cut the highway assistance program, or kill the microtransit program if they lost bus fares as there is evidence for assuming they would further cut bus service.