I wondered the same thing and, sadly, it wouldn't surprise me one bit.
Coach knows it has my business with or without the $50 off coupon. I don't shop much in the outlets and I often pay full price for things I love.
The last time I visited my boutique the SAs who have always worked there greeted me by my first name, as usual. There were a couple of new SAs there and I overheard one of them whisper to the manager, "Who is that?" and the manager's whispered response was, "One of our best customers." I don't think I am one of the biggest spenders but considering they know me by name and that I buy something every time I am there (usually over $100), you'd think I would have gotten the damn coupon.
I don't know how much effort Coach corporate puts into determining who gets what discount mailers, but I am sure they are able to pull their client list and filter it so that the "sure thing" customers could be excluded. After all, I'll be buying the things on my wish list with or without that coupon and Coach knows it.