I did the electrical and water hookups after the DW was pushed back to its final position. I used a flexible supply hose similar to washing machine hose instead of the solid copper that was used before. Luckily for me, my sink cabinet did not have a side panel next to the DW. The installation manual for the DW will show where the water/drain lines need to go in order to not interfere with the location of the DW itself. He could also go back into the wall by removing the sheetrock, but that could get messy.

If you have a lot of parties or a lot of kids and more dishes at one time than you can handle, the dishwasher is useful. It takes a modern dishwasher a couple of hours, and many want you to leave them longer to finish drying. I do entertain large groups, but my tableware for multiple dozens has to be hand washed anyway, and I can deal with running a couple of loads for a dozen or less, plus cooking stuff. A second DW can also be useful if you go through a lot of bowls. DW's seem well designed for all kinds of plates and cups, but not so much larger bowls. A wine fridge is great if you're really into wine, but if you were you probably wouldn't be asking this question. If you have kids or frequent feel-at-home guests who are constantly opening the fridge for drinks and snacks, an undercounter drawer fridge would be useful. I have one in my prep area which I use for must be refrigerated ales, opened wine (the bottom drawer is deep), root veg, butter for the stove (eggs, etc.), dried but must refrigerate veg, and the veg that are slated for the pot. It's also where I just defrosted the 21 lb. turkey that was too big for the meat drawer in my main fridge. I'm assuming you already have a trash pullout? That's what I put in a similar extra space. They're pretty much expected nowadays. Mine has two bins, one for city pickup recycling and one for deposit return. I don't like actual garbage inside the cabinet, but I find the pullout very useful because even with mostly scratch cooking, I have a lot of packaging. There's a drawer above, which is convenient for bottle brushes, wine stoppers, dish brush, drying pad, and other sink related things. By the sink is also a great place for wraps and containers, so you could just put in a drawer stack. What do you need most?

DH talked to him yesterday. He's coming next weekend. He thinks its a 'no problem' fix. I don't think he understands that there were plans he chose to ignore and the size of dishwasher we have is irrelevant. Looking more at the situation, I can see that he didn't want to cut the floor tile, so he just shoved it all in there. But I'll settle for him buying me the new dishwasher. DH insisted on this contractor. Minus this screw-up, he's cost me $2k extra in other mistakes. He screwed up the island, costing me a finish carpenter. He asked for extra cherry and rev-a-shelf pullouts that we didn't need. How can someone work as a GC for 20 years and be so clueless?

@myira - There is excellent advice above. I wanted to share two stories about my last house. We were moving from out of state with an infant and depended on our realtor and home inspector for a lot of things. Unfortunately the house we purchased was owned by a cheapskate DIYer sort and we spent lots of money fixing plumbing and electrical hazards that should have been caught on the home inspection. We were BFFs with the plumbing and electric companies. Both commented that they perform home inspections and that for a service charge will home out and look over a house someone is considering purchasing. I wished we had hired them to do a walkthrough in addition to the home inspector. It would have alerted us to a lot of problems for just a couple hundred dollars. Eventually we wanted to add on to the house but decided to move to a different place nearby to accommodate our growing family. We sold the house as is to a realtor who was also a house flipper. He made lots of cosmetic changes and we were very up front about issues we were planning to correct prior to moving such as new roof, rotting window, HVAC needing updated to properly service the bedroom wing, etc. None of those important things were improved or fixed when he put the house back on the market a few months later. I’m unsure of what he actually disclosed to the buyer. This is what concerns me about your situation so I’m glad you are seeking opinions and proceeding carefully.