It isn't something knew but the problem is some of the same issues the WT faces so does other churches. I feel the only way for them to lose their tax exempt status is when all churches do. This isn't something likely to happen soon.
The gay marriage upheld by the supreme court may cause that issue to be a reason.
In an op-ed published by Fusion, financial writer Felix Salmon made his stance on the matter crystal-clear in his first sentence: “Now that the U.S. government formally recognizes marriage equality as a fundamental right, it really shouldn’t skew the tax code so as to give millions of dollars in tax breaks to groups which remain steadfastly bigoted on the subject.”