The Macdonald flyover proposal was partly because of the hill, but not just that there's a hill there. It's because the current setup forces people coming from Dartmouth who plan to continue along North St. to not only go all the way to the bottom of a hill that they were already 1/2 way up, but to actually backtrack in the opposite direction and deal with additional road crossings to do it. That's becuse once you get to the bottom, you either need to walk up the left side of North St. since the road part goes in the opposite direction, or to wait for a traffic signal to get to the traffic lane going in that directin. So it's as much about the wasted time and being forced to backtrack in the wrong direction as it is the extra physical exertion. Yet with a flyover, not only would people not need to backtrack, go up twice as much hill, or wait for a crossing signal, you they can actually use momentum gained from going downhill on the bridge to propel a little ways up North St. So it solves several problems at once and saved a lot of time. It would be a time savings of 5, or even 10 minutes depending on the light cycle and how strong a hill climber it is. And that's a lot of time for just one intersection. But even if you just had to backtrack and waste time with a crossing signal, the current design still wouldn't be ideal.
But of course it was impossible for cyclists to go up hill, the Macdonald flyover wouldn't even be necessary since cyclists wouldn't be able to use the bridge to begin with. Because anyone who has ever biked over the bridge knows it is a rather large hill itself. Especially since it's almost always windy so there's often a headwind at the same time.