It’s a good surprise; I think last year it was a paid offering (not expensive though) from the CFL. They were trialling out the system during the pre-season and it’s the same deal as that.
I suspect part of this is due to ESPN in the US having dropped coverage from their part-owned Canadian partner. Which is strange, but perhaps the CFL didn’t want to see their games hived away onto ESPN+ like would’ve likely happened - so they are with CBS Sports Network this year, and US folk get what’s not shown there on the CFL web site too.
Always liked the much more subtle visual look of TSN’s Canadian gridiron coverage to that of the NFL - always been of the “the game should do the talking” kind of mindset - but that speaks as much about the two countries and the two codes as well.