Our family friend, for many years a Catholic chaplain, said that one of the happiest embarrassments he had was all of the Protestant enlisted men converting to Catholicism!
When his fourth Baptist chaplain did (as they were exiting the chaplain corps - for otherwise, of course, they would HAVE to leave), one of the leading Protestant chaplains said to him, "Hey! Stop stealing our ministers!"
Not sure it was hyperdenominationalism . . . sounded more like people in multiple subdivided denominations realizing that Christ who prayed, "that all may be one," must have left behind one Church, and it probably was the one with Peter (and his successors) as its visible head and where, as in both John and Luke/Acts, the Mother of Jesus was a welcomed presence.
See #102.
As a longtime chaplain, I think your friend overstates the case. There are those changing denominations all the time. All sides, by the way. There is a constant shuffling of folks.