It's simply not acceptable to be tracked from one side of the country to the other, with a slot time, and COBT compliant to then be treated as a shock/ surprise at 200 miles.
Not acceptable..hmmm. I suppose one of the solutions to this then is to deny any weather deviations as it may delay following traffic who are otherwise compliant. That ain't gonna happen.
BTW, we used to give higher priority to certain long haul flights, but the airlines (ie. your bosses) felt it no longer required or didn't negotiate for it's continuance.
These complaints are about as fruitful as your pax whingeing when a flight is cancelled 2 hours before their flight, even though they booked 6 months ahead.