Costco does usually have good prices on appliances, especially during their sales. Also like the "idea" of an extended 2 year warranty as most modern appliances have gone to only 1 year at most (thou realizing a warranty is only good if it is lived up to, and luckily haven't had to rely on it!). But, as for installation, I have run into the same issue on two appliances purchased in the last year, a washer/dryer and a stove. Costco has included delivery, installation and haul away in the pricing, but on both the dryer and stove (which were gas), the installer on each arrived with the incorrect size connection line. Both times they indicated they'd have to return with the correct line and both times they never came back. In each case I had to purchase the line and install myself. I reported to Costco, but I believe they are merely the middleman between the appliance manufacturer (who they send the order to) and the manufacturer's installation contractor.

Unacceptable
 

They never came back! That is unacceptable but unfortunately happens too often here in TV with 3rd party subs.

We too had the same issue with Home Depot. Not knowing about the Accor style ice maker valves, we fell for the new water line pitch. They cannot put on the new water line, the Accor valve has the ice maker line permanently swaged onto the valve. There is no issue in reusing it if the rubber is serviceable in the 1/4” compression end, ours was not. And unlike toilets and sinks, the little rubber compression washer is not available. Thus, it’s best to replace the valve. They really aren’t that hard to do and there’s a half dozen videos how to do so on YouTube. Ace has the superior shark bite ice maker replacement valve and the braided line.
As others mentioned, you most likely will need to trim the cabinets above, for the new refrigerator especially if it’s a counter depth style.

Dealing with Home Depot is no better. It’s a long story but in a nut shell we’re done with them!! Seems like we can’t depend on customer service completing an order.

Ours has adjustable feet that you use an open-end wrench to adjust, normal right-hand thread, you can loosen the foot, and then you should be able to pull the refrigerator out. I usually place rope or a flat strap behind the unit, so I have something to pull on. I would normally agree to help, but my knees get easily annoyed with this type of work. There are several handyman on this site that should be able to help you.