Why make an indefensible claim?  It was widely reported in the MSM back when Reince Priebus first talked about this in February.  It's a settled question -- that's why the MSM isn't still chewing it over.  There's a reason "news" contains the word "new", you know.

Would you consider the NYT and the Washington Post pre-eminent representatives of the dreaded MSM?  Trump clearly does -- he's cited them many times in his tweets.   Both of them reported on this.  Here are but two examples, one from each paper.

https://www.nytimes.com/2017/02/23/us/politics/fact-checking-claims-about-trumps-travel-ban.html

https://www.washingtonpost.com/news/fact-checker/wp/2017/01/29/trumps-facile-claim-that-his-refugee-policy-is-similar-to-obama-in-2011/?utm_term=.d0145b533169