I hope not as well, though I'm a little nervous about what 2K expects.
My general thoughts: Almost no one plays scenarios. Multiplayer has had limited long-term engagement despite multiple attempts at shorter variants (or even completely different variants like pirates/red death. There's a lot of single players, but they don't have an AI that challenges people at the higher levels. They see some friendly competitive engagement on forums in things like GOTM or fastest science victories.
They might be trying to solve a lot of those with this. Interesting GOTM scenarios potentially coupled with some sort of iron-man/competitive leaderboard sort of ranking per scenario could engage single players and bring some of the competitive element people lack from the AI (and as an alternate to multiplayer). I don't know about the second part of that though honestly (the competitive leaderboard style of implemenation) since preventing cheating would likely be very difficult/resource intensive.
Yeah it seems more like a sort of dedicated scenario with a mild competitive aspect rather than like a true "challenge olympics" or something. I mean, we haven't had anything like this in all the time of civ, and it's mildly codifying like an official GOTM with a quick setup accessible to everyone.
Obviously if the challenges come back in 7, I'd want more from them. Fully open difficulty levels, give us some more curious custom map designs, etc... Even if they bring in some hidden extra changes (ie. like suggested above, maybe for this scenario only they change Babylon to be zero science naturally, but like every time you build a building or district giving science you also get a free eureka or something even crazier). But even without that, I don't hate these as like a casual way. I played a couple of them after having set aside the game for a few months, so obviously they were curious enough to give them a try.