The mainline denominations continue to lose members ... could it be that, by abandoning everything traditional and turning to secular humanism [at best], they have lost what church is supposed to mean?
I believe that I visited this parish in OKC many years ago during my travels during my Anglican days. It seemed like a pretty healthy place.
In general, traditional parishes are not bursting at the seams, whether in the Anglican or Catholic world. Within Orthodoxy also, those "traditionalist" parishes don't usually grow very well either. The idea that if one is modernist that the church will shrink and that if it is traditionalist it will grow has not really proven to be true "on the ground." Continuing Anglicans were beginning to realize this by the mid 80s.
I think the key is whether a parish is concentrating on being "traditional" or whether they are concentrating on being Christian. Many "traditional" parishes are more concerned about what they are not than about what they are.
The parish discussed in this article seems to be successful because they are concentrating on being Christian (which should include being faithful to all aspects of one's tradition, including liturgics, dogma, and morals.)
Parishes with the vibrant combination of tradition and true Christian love nearly always grow, both in numbers and in spiritual maturity.