Its all about communication with your visitors.
I would definately remove the programs from your warning pages/blacklists that have come back into compliance with acceptable business practices. I would post a notice that presented the change in a POSITIVE light similar to this:
“We have great news! Several of the casinos listed here have been removed from our warning list due to positive changes within their terms and conditions. We now have complete confidence recommending them to our players.”
It comes down to semantics and how you present the statement. Rather then viewing it as “Damage Control” and something you have to apologetic about, present is as the positive development that it is.