Yes I agree Dick- the people will decide about whether a song becomes 'traditional' in your terms & probably not for years yet, so there's a chance for Buddy Holly - mind you his stuff seems well on the way to me, although his songs are not nearly as popular in 2019 as some if similar vintage- eg 'Que Sera' - I don't have a high opinion of that song, but it's not down to ME to decide.

It's only when you try to allocate songs to categories in advance of that process that you get into trouble!