I received the same letter today. Doesn't say anything about the Loyalty Program. Where it mentions the $1,000* bonus it says....
In addition, if you bring this letter in between now and July 31st, we will give you a
$1,000* bonus toward the purchase of your next new GM vehicle. Our promise is to continue to work hard to keep you in our family, providing some of the best quality vehicles in the world.
In the fine print it also says..."This offer may not be combined with certain other consumer incentives available on GM vehicles."
The way I read it is if it is not the Loyalty Credit, we won't be able to use it and the Loyalty Credit together.