They'll announce on the tumblr or the intro or in a promo whenever a schedule change is occurring.
You wont however know what the episode number of any of the shows are unless you compare the name to the episode numbers on a wiki or something.
Really I'm much more annoyed that we just lost the most reliable schedule for Adult Swim's weekday and Sunday line-ups. If they actually play something other than Robot Chicken, Aqua Teen, Squidbillies and the usual FOX shows outside of DVR Theater, we'll only be able to find out a week in advance at most. They just recently threw on China, IL on the weekday line-up and I wouldn't have been aware of that if it were not noted on that schedule. Likewise they briefly took away one slot of DVR Theater and I wouldn't have known that had I not seen it on the "on air" schedule. Speaking of DVR Theater what's the point of having something intended for being recorded by the DVR if you can't plan ahead for when you want to record something with the DVR?
If they ever make a goof on the episode they are airing again we should remind them that such things might not have happened if people looking ahead on the "on air" schedule had noticed the wrong episode was listed for the night.
You should tell them this on tomorrows Q&A. I think it explains quite well how we all feel about the death of the on air schedule. Really well put. Perhaps add that they could just write Toonami in place of their shows or some other suggestion.