Radio Reference has no control over that; it's up to the owners of the repeaters to decide if they want to share the audio. And, from what I've read elsewhere, some repeater owners wanted to use higher quality settings than what Radio Reference allows and have decided to find other hosting services instead.
When you say 'showing' do you mean in our database?
You should be aware that the admins will not take data directly from some website - someone has to validate that those frequencies and sites are all active, and submit them to the database. This is policy.
Understandable - after all how could they know which sites are up and which are not?