"Would it make any difference in metro revenues?"

Yes, it would hurt revenues. One bike takes the space of three standing passengers, and even more space for maneuvering. I've been on plenty of trains outside rush hour where it is honestly difficult to get a bike through, i.e., so that I'm not blocking the doors that are going to open at the next station.

As the Human Transit article notes, most bike-friendly countries don't have a culture of bringing bikes on trains -- throughout Europe, bikes are typically treated as checked baggage aboard trains. Instead, rail stations in Denmark, Japan, and the Netherlands are surrounded by thousands of cheap "station bikes" that passengers ride to/from the station. Bike sharing can help to consolidate at least a few of these bikes in higher-density areas.