Yep, most will simply adjust the local water profile to suit. Secondly, each style of beer has a different profile required for best effect, meaning that the water is always treated, no matter what. I also find the story about XXXX interesting as I don't understand why that beer wouldn't have had a profile as part of its standard recipe.
The big breweries use mechanical separators instead of fining agents and temp? It's an honest question, I only know craft processes, I wouldn't have a clue how the commercial swill processes work.