There will be some uncontrolled left hand turns terminated, but there will never be another interchange/overpass built on the #17.
The McTavish interchange was 100% a product of the airport, not residents living in the area.
Take a look at Google Maps and scan up the peninsula, there simply isn't the density between Royal Oak and Sidney to support one $50 million dollar overpass (let alone a series of them).
With the Malahat begging for something to be done, and nothing in the works, the relatively calm Highway #17 isn't even on anybody in authorities radar.