No, there was one other interesting point.

Management wanted a "big splash" public rollout. Development teams wanted to avoid a "big bang" development effort. They solved this by going live many months ahead of time but ONLY for clients using special headers. This allowed anyone to test the system while still not making it "public" until the day of the big reveal.

I had not previously heard of that particular technique (using special HTTP headers) and it's a useful one.