All those networks have a "home" channel that they began broadcasting on and developed into a nationally recognized brand that became basic to any cable package. Rights negotiations are done with the understanding that the sporting event will not be shuffled off to some secondary channel.
Rogers has no such "home" channel. That's the difference. What is their default national channel? There isn't one. ALL of their channels are secondary, besides the regional network, but that is only non-secondary in its own market. SN1 could become their national default, but is not included in most basic cable packages.
They'll broadcast the marquee matchup on Sportsnet. It's not that complicated. CBC has CBC Vancouver, Toronto, Winnepeg, etc, etc. It has no problems doing nationwide broadcasts of games throughout its network of stations.
And they even demonstrated this in their sample Saturday Night schedule. All the main Sportsnet stations will show the same game, Sportsnet 1 will get different game.
It would be extremely short sighted for Rogers to do any of what you keep confidently asserting they are going to. Rogers has been trying to compete with Bell and TSN for sports supremacy for quite some time. They aren't going to pay $5.2 Billion to put marquee match ups on a channel not many people get. They will focus on it, and use it to increase their own brand, try getting people to tune into the pre-game, Sportsnet Connected, etc. This deal is about a lot more than simply the 3 hours a night they may televise a game every other day or so. It's about trying to make Sportsnet the go to sports station in Canada, and you don't do that by hiding your best draws on obscure channels.
TSN didn't do it with TSN2, and Rogers won't do it with Sportsnet 1 or 360. The biggest games will be on either the main Sportsnet network, or on CBC.