Just approved for Sapphire Reserve and lowered my limit from $10,000 to $1,500 before I even received the card. I did the same thing with the Chase Ritz Carlton Rewards card and I avoided the annual fee for the first year. This hack was widely reported on numerous sites. Google "Ritz Carlton annual fee hack" and you'll see. Both cards are Chase and both are Visa Infinite program, so it will be interesting to see if this works again. Once fee is not charged I will transfer some credit limit from my Freedom back to my Reserve so I will have higher amount and can easily meet the $4K for the bonus.
Per the Credit Card Act from 2009 credit cards cannot have an annual fee that exceeds 25% of the credit limit.