When you say it's not usually done, do you mean that Persichetti intended for it to be done that way? I haven't heard any other recording that did this.
Been familiar with this symphony for a long time, but had no idea the melody of the 2nd movement was based on a hymn... the harmonies are definitely Persichetti's own, though. This was some serious creative liberty taken on the part of the ensemble/its director... I think it's incredible. Who knows what Persichetti would have thought. And who cares, really!
That's what I thought, too, but then I started wondering if maybe there's been a reprint with a slight change? It didn't sound bad, necessarily, just different.