OK, texted with guy in NHL, he said it was important a couple of years ago when localities started complaining players were not playing and the league sent out a memo. It affects the highest paid players who will be tracked as it is a lot of money. Up to individual players though and tracking who was on the roster and played that game is a lot of work. He said he does not pay the taxes as he is a lower tier player, and the amounts are so low that it will cost more to go after him. As far as spending the week in Cali, he can't imagine a player paying for all those days in taxes instead of just the three game days.
Also said it is absolutely a part of a players signing to account for taxes and cost of living. Again, the lower mid-tier type guys.