I think they're referencing this analyst-claim: https://9to5mac.com/2018/01/19/kgi-lowers-iphone-x-sales-est...

I tend to be skeptical of such analysts, though. Not that the ultimate claim of "the iPhone X's advances and form-factor are going to be moved into all the other models" is terribly controversial -- that's pretty literally what Apple said would happen. Just that it's a person guessing, and such things have been fairly spectacularly wrong in the past.

Ming-Chi Kuo at KGI Securities

http://www.valuewalk.com/2018/01/iphone-11-release-date-kgi/

https://www.yahoo.com/news/iphone-x-may-discontinued-next-fa...

Thank you. :)