Again, I doubt it. NASA funding doesn't really work that way. They don't get a big bucket of funds to distribute as they please. SLS was the pet project of a number of powerful Senators, to the point where the joke is it's the "Senate Launch System", and has been specifically appropriated for by Congress.
There are ALWAYS politicians who are happy to give the money to their project. The idea that NASA budget would go down by 5 billion $ without SLS/Orion isn't really credible in my opinion. Some projects would be done, because Senators in space states wouldn't want the budget to just get lost.
