If your family members need binaries of bleeding edge software and you're worried about their ability to use their computer you should be building them. In that case you'll be able to ensure compatibility. I don't think encouraging novice users to download random binaries from the web is any better than them not being able to use the absolute latest version of an email client.

Aye, but it's still a valid concern in a technical sense. They're not great for things outside of certain bounds of LSB

With that said/considered, I don't think it's a big deal - anyone non-technical should be happy with whatever their distribution maintainers provide.

They won't be watching mailing lists hoping to grab the latest $thing :)