The ONTC bus stops at a Service Ontario office parking lot at the far end of Main Street (Muskoka Road 3) near the Highway 11 interchange. It's a long way from the town centre, though there is a limited transit service that stops there too (I think it would be better if it stopped at the A&W or Tim Hortons at the Muskoka Road 2 exit). I don't know if it ever stopped at the train station, but ONTC moved its buses away from other old rail stations where they used to stop at, including Gravenhurst, Temagami, New Liskeard, and Matheson.
One problem with using 'fast food' places is their parking lots and entrances don't always lend themselves to highways coaches (heck, many don't lend themselves to passenger vehicles!) The Tim's at MR2 can be particularly egregious, as many of them are, especially in the summer. Also, people dropping off/waiting for arriving passengers fighting for space with restaurant and drive-thru traffic. I would assume the Commission has some kind of minimum standards for station access (i.e. clearances, sightlines, pedestrian conflict, no reversing, etc.)
The roadway down to the Huntsville train station, along with space to turn around, might also be problematic for highway coaches as it is currently configured.
Maybe once the train is back they can start using them. Even better if there were buses going north and south at the same time, or within a reasonable time so that you can use the bus to get to your final destination.
Side note, does anyone know i NB transit services the NB bus/train station?
Perhaps. Many are either municipally or privately owned now and they would have to negotiate with the owners. Quite frankly, not many communities along the route have municipal transit and I'm not sure there is much market for intermingling ONR rail and bus schedules.
Re North Bay transit - not directly. A route goes to the Northgate Mall which is on the opposite side of the tracks from the ONTC station, and there is a pedestrian tunnel under the tracks. I'm not sure how convenient it is to schlep you luggage into the mall, through the mall, then back outside again and through the tunnel. I don't know why they don't service the ONTC station directly (or if they ever did); perhaps the bus/train frequency doesn't justify transit frequency service.