If exclusives are bad for business they will probably go away. Businesses are generally pretty good at learning what's good and what's bad.
I don't think they will go away. If the property is hot: Most of the people who would have bought at launch will still buy it after the port, and you can take that time to learn what went well in the first launch to make your second launch go even better. If the property is not hot, you may get more purchases as the exclusive because it's a perception of value, and you are a bigger player in a smaller pool. And hey, you also get whatever the platform gave you for being exclusive, which is usually a better deal, and lowers your risk.