Part of what he says might actually sound familiar to some fans, though. While Far From Home is firmly rooted in one universe and one universe only, Beck's mention of the multiverse includes a couple Easter eggs for all of the die-hards out there. "Earth-616," which Beck referred to as our Earth, this movie's Earth, is a real term used in Marvel Comics mythology to describe the universe in which most of the action in the main continuity happens. Earth-616 is also the in-movie designation of the Marvel Cinematic Universe, though if we wanna get real technical, the movie versions of the comics (starting with Iron Man and excluding the X-Men, Fantastic Four, or any Spider-Man movie before Spider-Man: Homecoming) actually take place in Earth-199999. Just something to whip out at parties when there's a lull.
The concept of the Marvel Multiverse was first introduced with the creation of Captain Britain, who learned that he was part of a team of Captain Britains all throughout the great Multiverse, each one tasked by the wizard Merlyn with… upholding the laws of Great Britain. That's cool. That's nice for them. (The characters in Captain Britain comics were modeled after those in Michael Moorcock's 1970 fantasy novel The Eternal Champion, where he first coined the term "Multiverse.")
Earth-833 is also a real universe, even though it's fake in Far From Home. In the comics, Earth-833 is the designation of Spider-UK, a onetime Captain Britain who inherits Spider-powers and is forced to live out of his own reality, popping from one world to another, as his universe was destroyed in something called the Incursion. The Multiverse is especially pertinent to Spider-Man comics: all universes exist within the Great Web, which is presided over by a number of godlike Spider-Totems, and in which first originated Spider-powers. Like every universe has its Captain Britain, most of them have their Spider-Man, too -- which is a concept that Into the Spider-Verse managed to sorta delve into in a couple of scenes. You actually see the physical Great Web during every sequence in which a character explains how they ended up in Miles Morales' reality.
This is a really lo-o-ong way of saying that this thing we all thought might be in the movie is not in the movie, but, who knows? With Marvel getting more ambitious and wild now that the Avengers are all but done (Eternals, anyone?), we could very well see a Spider-movie introduce the Great Web into the MCU in a more official capacity. It's a weird, complicated, confusing concept, but let's not forget these movies once convinced us that a raccoon and a tree have daily chats in outer space.