Denied Application because of the “3/24 rule”..?

Hi all! I tried to open up a Chase Ink Preferred card about a week ago, and about a day after sending my application out, it got denied due to “number of recently opened cards”. This, as usual, seemed to be a “5/24 rule”-style denial, so I went to the reconsideration line to get it sorted out because I assumed the issue had been that my 2 authorized user cards got counted under my profile.

However, after a wild goosechase and getting transferred to a new agent about 15 times, a lender told me something very weird.

“You got denied because you had too many recently opened cards. Two capital one cards and one Chase card”.

And I of course questioned this because this didn’t make any sense, and asked “so there is a 3/24 rule”? to which she replied yes, and clarified that this rule exists just now, starting this month.

Has anyone else run into a similar issue? Did Chase seriously just silently roll out a “3/24 rule” this September, or did I just get very very unlucky?