My personal disappointment with hockey rinks and mounties were fourfold.
First, there's no natural fit between these and Civ gameplay. So as a result, as I feared, the dev team created some bonuses and then called them "hockey rink" and "Mountie". We want Canada to get more food and production from tundras: call that "hockey rink". We want Canada to be able to get national parks more cheaply: call that "mounties".
Second, the opportunity cost for that is it means other uniques that Canada could have had, that fit more naturally into Civ gameplay, get dropped. Fur Trading Posts as a unique improvement and Coureurs des bois as a unique unit fit very well in a game about exploration and settlement of new lands. Or any of about a dozen other suggestions from the Canada thread.
Third, Civ is an opportunity to explore an interesting aspect of a civ's history. There's a lot of interesting parts to Canada's history that would fit well in Civ: the exploration and settlement of a new continent, the opening up of that continent through the development of the railway and settlement of the west, the development of UN peacekeeping missions, etc. Hockey rinks don't tie into any of those, and mounties only tie into the railroad and settlement of the west (which is why I argued a Mountie Fort could be a good unique improvement, even though a mountie unique unit was likely to be a poor fit). So we don't get any of that. Instead we get Canada as a tundra civ, a role Russia already filled.
Fourth, Civ 6 is on it's second expansion, and at this point in the cycle, a new civ really needs to offer some interesting and unique gameplay opportunities, something different than you can get from playing other civs that are already in the game. Unfortunately, hockey rinks and mounties as portrayed in Civ 6 don't contribute to that. Other than the "no surprise war" thing, this Canada civ seems like a waste of a civ slot compared to what could have been done with Canada. And the main reason for that, it seems to me, is the dev team was set on including hockey rinks and mounties, preventing them from seeking out more interesting things that could have been done with the civ.