"...simply rearrange the existing members...."

Quite on target. There is no great diminishment among the "nones," owing to this pseudo-demographic "surge," as it were (in the big picture of things). For that reason you see "official churches getting along with great respect," as, for example, in Washington, D.C. (with Cardinal Wuerl donating money to  repair minor damages at Washington Cathedral [Episcopal] a few years back ) and even in Rome (in meetings between the Pope and Archbishop of Canterbury).