115 Silver Hills could have been routed to serve Oriole GO station and Leslie station, but no, the people of Silver Hills would rather go to York Mills station instead.
115 already serves Oriole GO.
Not sure how running 115 to Leslie does anything but slow down most subway riders commutes.
The one they SHOULD have extended to Don Mills or Leslie is the frequent 91C and D Woodbine service, which terminates only one stop from Don Mills Road, at York Mills and Silverdale. From there it's only 5 more bus stops to Sheppard (though running it up Valentine, Fenelon, Graydon Hall is tempting)! The service is quite uni-directional, especially north of Lawrence.
As it runs past the Line 5 stop at Bermondsey, I'd assume that it won't survive what would have to be major bus route changes when Line 5 opens. Presumably a split at Eglinton, and hopefully a relatively quick Bermondsey to Don Mills station bus.
It could also run down York Mills, and up Lesmill to Leslie, providing service to the unserved chunk of Lesmill north of Duncan Mill.
Come 2021, TTC will have better access to UPX/KW lines for Dundas Subway, but still a walking trip for buses and streetcars riders, but better than it is today.
Walking in a tunnel though though with the tunnel being about 3o metres long, and
The other 2 still requires long walks, but Oriole should be closers to the Leslie Subway than today.
With them moving the platform, it will be. If they'd put a walkway over Leslie Street, it would be a simple 150 metre walk to the tunnel from Leslie station to that new office tower to the west (what happened to that anyways, I thought it was all approved years ago, with the approval to remove the knockout in the station as well).
Presumably there's another knockout in the south as well - that TTC parking lot south of the station would work much better as a building, and put the platform only 100 metres from a sheltered walk to Leslie station. Could probably do a no- or low-cost deal with the land to the south as well, if it included access to the walkway over Esther Mills - heck cover that, and it will feel like they are connected.
And a shorter walk from the planned western entrance to East Harbour station (were I assume there'll at least be a TTC bus stop), to the attached Downtown line subway platform.