If you're already out and near downtown and want the money sure! Otherwise if its a good event they promote the event in the app and get a whole bunch of rides out quick. It prevents surge. Its best when Uber has no idea how many customers will use it and fail to promote it.
I was driving during BOK's Sugarland country and western concert last night (7/20/18). I took five rides to the BOK center - three of them were XL rides. There were a couple times where surge pricing showed up over the downtown area but I never got a surge ride from it.