Large Urban areas like Toronto and Montreal continue to overall lose population with rural areas experiencing record growth.  Most of this loss is related to the price of housing and cost of living in large urban areas that are becoming out of reach for many people.

Looking to the future, how will this impact radio?  Will major market radio lose listeners, become less important and influential with smaller and medium market broadcasters experience the bulk of the growth with audiences and revenue?

Living in the K-W/Cambridge/Guelph area I can say that we have been booming over the past ten years or more.  Construction is everywhere for condos, homes, infrastructure, transit even industrial parks have been expanding.

Local radio here regularly has advertising for companies looking to hire with full time jobs, signing bonuses and benefits.

Looking at where new radio stations have been signing on are in secondary markets outside of the GTA. Some of these stations have been regular commercial outlets and others community stations, but many sounding similar to regular commercial radio.   Toronto does have a problem with a lack of FM frequencies available, and for now this doesn't seem as much of an issue in many smaller markets that are all experiencing record growth. 

More on the Toronto/Montreal population decline from Heromag. https://heromag.net/toronto-montreals-population-is-declining-as-urban-flight-accelerates