Certainly reason for concern, not only for you, but for the rest of us in this make everything the same production world. Wasn't even aware plastic quick couplers were used on this vehicle until this subject came up. And not even sure how the heater core is made. Traditionally, was the last component or least it still be so to be made out of brass. Plastic tanks on aluminum radiator cores was the first component to introduce new problems. Its cheap.
Our last radiator repair shop died about ten years ago, brass could be cleaned like new with acid, and soldered. Can't do that with aluminum, will boil up and nothing will be left with it. Solder was replaced with a neoprene gasket that dries up and decays into dust and is crimped on, can only crimp once. Old fashion guys that thought stainless steel screw hose clamps were better to replace those spring clamps. Not true, those spring clamps can expand as plastic has a very high coefficient of expansion, that plastic because becoming brittle with age will crack. Radiators as well as condensers became throwaway items.
In particular condensers, if your compressor leaks out some oil and with R-134a mandated by the government, compressor will seize and load that parallel flow condenser with debris that is positively impossible to get out. Another throwaway item. With tube and fin condensers used with R-12, can be easily flushed out.
Think back to the 60's when Chicago was the electronics leader of the world, had plenty of work to do, in one months paycheck could afford to pay cash for a new 65 Buick fully loaded Electra. Loaded with chrome inside and out, even had a bumper jack where the bumper could lift the entire car. Sure can't do that with a cheap plastic bumper and your safety comes with the same kind of polystyrene that you get in throwaway packaging.
If Chevy cheapened that all important heater core that can kill you, that is going way overboard. Certainly reason for concern of all of us. Not kidding on this subject, know people that died with kidney failure caused by breathing anti-freeze.