I found it.
The language was: "If your App is rejected, we have a Review Board that you can appeal to. If you run to the press and trash us, it never helps."
This language was on the current "App Store Review Guidelines" page [1] from when it was first published around September 2014 [2] until on or before June 18th 2016 when the bullet vanished. [3]
I think this is a very important line because this page featuring this language appeared literally a month or two after I published an appeal for our late app, Gliph, which was pulled from the app store over Bitcoin transfer capability. [4]
I don't think we were trashing Apple, but the press does like to make hay out of these moments.
I'm not sure how anyone could interpret this line except as having a purposeful chilling effect on trying to build public support for your private case with Apple.
This is particularly notable because I believe there are multiple occasions where Apple changed course solely because something got press coverage.
Perhaps Apple is okay with going to the press, but only if you do so with positivity? How is this really possible if you're making a case that is in opposition to the findings of Apple? Also as I mentioned, you can't control the editorial decisions of press in giving a story a negative spin--the press makes money from clickbait.
So this line had speech-limiting implications.
--
Having gone through a ton of updates of this page on Wayback Machine, I think there's a great study to be done on the evolution of content.
Two things that stick out to me are that the language used to be pretty heavy handed, even dark. It read like someone who was kind of mad.
Now it is very positive sounding and has a last updated date.
[1] https://developer.apple.com/app-store/review/guidelines/
[2] https://web.archive.org/web/20140903022336/https://developer...
[3] https://web.archive.org/web/20160618044341/https://developer...
[4] https://news.ycombinator.com/item?id=23580250