On the subject of the thread, I went to a C of E school in the 70s/80s (daily religious assembly/hymn practice on a Friday) and have worked on supply in C of E and Catholic schools recently. These days it's called 'worship', it's not daily and then don't have hymn practice but they do still sing. And they do still sing songs about God, because they are designated faith schools. But they aren't necessarily what you think of as classic hymns like All things Bright, or We Plough the Fields, just as in my school days we sung 'Magic Penny', 'The page is black', etc. Sure, we did some of the oldies, but, just like today, we sung more modern songs, some of which were written off school assemblies.
I don't recognise most of the songs I have heard in today's religious school assemblies, and it's fair enough, it's a new generation and people are still writing religious songs. There's been a lot of modernisation in church music, there's Christian rock bands now.
If we want young people to 'keep the faith', they need to be able to 'own' it. My mother wouldn't have sung 'Magic Penny', just as I don't know a lot of today's assembly songs, but I think that's how it should be. They also have their own Christmas Carols, although we still have kids lisping through 'Little Donkey'.
Culture doesn't have to mean what we all remember. It's perfectly reasonable for the culture of Christian worshipful singing to move beyond songs written pre-1900. If there weren't new Christian songs being written, we really would be losing any sort of Christian identity.
Perhaps instead of the kids having to learn the old ones, modern churchgoers should be doing more of the newer ones, so that Christianity today looks like a part of modern society rather than an anachronistic relic of the past.