Interesting history...it should theoretically taste the same, I guess. But as someone else mentioned, it might be sourcing of ingredients, etc. It isn't necessarily bad tasting, just definitely different. My husband thinks so, too. I don't think my tastes have changed, either. I brought back a couple of cans of Campbell's when I was in the US for Christmas and it still tastes as I remember it. I may have to try Bachelor's again and see if I can get used to it.
I'd be interested in anyone's recipes for homemade bases. Green bean casserole is just canned green beans mixed with condensed soup and then topped with cheddar cheese and baked. So the cream of mushroom soup being such a key ingredient, you can really taste it. I make some other casseroles that use the soup as a base, too, that have more ingredients, so I will have to try it again maybe.
The Heinz non-condensed soup tastes quite good to me, so maybe I will just have to start making larger casseroles to counteract the extra-runny factor.