LT, I'm in no place to offer advice, but I can offer possible things to consider....I'm reading and following... Bumping you up to the top, maybe someone wise has some ideas....
It is tough, when you see the kids struggling with the changes. Many things could happen by bringing it up, especially if it is received as criticism. You could be blamed for brainwashing (I got that one), your W could actually agree to have D's spend less time with her (depends on whether her priority at the moment is either control over the agreement, or freedom from responsibility), she could dismiss the issue, minimize and avoid, she could spontaneously combust....being ready for anything is always a plus for me, but having no expectations is a must.
I keep reading that as long as you keep expectations at zero, and don't take bait and turn into a fight.....idk. Might be ok to bring up. I would say just don't expect the results you're hoping for.