Your review sounds like you had a lot of bias going in, expecting the park to be bad or something. I don't think WMG's station is spectacular, but I wouldn't consider it unfinished.
Just had to point out though, you don't need to sign-up to use the 407 toll highway like you said, it's the same as pretty much every toll highway, cameras capture your licence plate when you enter and exit and you're billed directly vs having to stop and give an attendant change like old school. The sign about Non-Ontario plates will be billed, is to remind drivers that aren't from Ontario that the highway isn't free for them and that they will also be billed. You have the option to sign up and buy a transponder which goes in your window, which avoids the video toll charge each time you go on it so saves money for people that use it often. Just checked the 407 site for you, looks like your plate is dirty or covered:
IMPORTANT: A $50.00 Unrecognizable Plate Charge plus tolls per trip are billed to light vehicles without a valid transponder whose rear licence plate’s identifying features are altered, not visible to or recognizable by the toll system.