Yeah, that does look like a problem.
But with Ontario line, the tunnel portal is below the edge of a cliff, so not sure how accessable a bike path would be for snow clearing equipment.
Maybe there'll be an costed option to add it. That was the case with the North Arm Bridge for Cnaada Line.
The bridge will also be designed by the successful proponent - that's why this rendering is 'conceptual only'.
So it may be cable stayed or extradosed as those are usually cheaper.