In Wisconsin, they added an open fixed category to all the USA Cycling crit races last year and are continuing it for 2019. It's a 20-minute race that goes off at the end of the day, around 5pm. I didn't try it last year, and the results showed really small fields -- in one case, I think 2 riders. I don't have a fixed gear bike anymore, but started to look around, figuring they'd be everywhere for cheap since I thought the fixie craze was over. But I had a hard time finding anything. I thought there'd be a bunch of track-ish fixies for $400-$600, but not that I saw. And there aren't a lot of companies turning them out new. Trek used to make a fixie; Cannondale had the Capo -- not sure how many big manufacturers are interested in this product anymore.
I question the notion that it is a way to get people into the sport; to me, it seems more intimidating than riding a road bike in a crit. And at least here, I see smaller and smaller crit fields across all categories.
One thing that I do find encouraging about the road racing scene -- crits in particular -- are the videos that Trainer Road are putting up on YouTube. They are really fun, useful videos with great discussion. I love them as a racer, but I also think that they really invite people to try racing.