SPIDER-MAN: FAR FROM HOME Digital Release Throws Water on FANTASTIC FOUR Easter Egg Theory

So it wasn't the '4' as in Fantastic Four in FAR FROM HOME's final scene. It was another '4' of MCU significance.

via The Nerd Machine

https://www.newsarama.com/45861-spider-man-far-from-home-s-other-big-mcu-teaser.html