I don't see any problems with this , especially as it is an area that has been pushed out by other priorities.   Some of my main memories from primary school are the singing together radio programmes.
As for singing what you wanted to sing - don't remember that every being the case in class excepct on very rare occasions or when you got to choose from a selection. Even without a national curriculum schools will avoid problematic songs - however you define them and I have no doubt that there will be issues but that is all out weighed by giving kids the opportunity to sing at a point when most of them genuinely enjoy it.

nice to see Howard Goodall involved

J