Uber presumably takes a fixed cut of the fare, so they have at least some incentive to look the other way during surge collusion. If the drivers do it simultaneously to both Lyft and Uber then both companies will be happy to see this going on.
This is not in Uber's interest. From their perspective the purpose of the surge is to get more cars on the road. They don't care about drivers, they care about fares (riders).
As far as I know, Uber does not take a cut on surge pricing. The extra money goes straight to the driver.