Shouldn't some of these runs become obsolete because of the new rule about top 30 runs needing sound?

since these runs where done before the rule was added, I think its fine if they stay. but thats just my opinion.

You mean rejected, and I agree with @jensj56

yep, rules are applied for new runs, we are not removing any run that doesnt fit a new rule if it has been done before the application of said rule