Back in 2011 the City of Toronto approved various modifications to the western end of the Gardiner, including adding a lane between the Lakeshore Exit and the Collector/Express system:
It's not clear if the City / now Province still intends to proceed with these or not.
The City also had plans for more ramp reconfigurations within the downtown pre-upload, it is also not clear what will happen to those.
Post-upload I could see MTO addressing substandard interchange designs (especially on the DVP), but over a span of many decades. The real answer is that we simply do not know.
I also imagine that maintenance will shift to be closer to how MTO manages other highways - that is, without entire weekend closures.