Once you get over the delight and shock of Simmons' cameo, you can start to consider the implications of it. There are already a number of people aware that Peter is Spider-Man: Aunt May, his best friend Ned (Jacob Batalon), all the Avengers, and, in Far From Home, MJ figures it out. Still, he's been holding out hope of leading a double life and existing as a normal high schooler when he's not in the suit. Those dreams are now shattered. However, the turn is perfectly in keeping with this franchise's ethos. Ever since Tony Stark declared that he is Iron Man, these movies have largely ignored the notion of secret identities. Holland's Spidey was the last bastion of that trope.
And yet, somehow, the concluding sequence also brings the MCU Spider-Man closer to the world of Spider-Man canonized in the Sam Raimi films of the early 2000s. For the first time, Holland's version of the hero is going to have to deal with public animosity, personified in J. Jonah Jameson.
Of course, this is a new spin on that character as well. He's no longer the gruff newspaper boss hungry for photos that will make copies of the Bugle fly off the newstand; he's updated for the contemporary media climate, echoing the way he appears in the popular PS4 video game, where he's a pissed-off, reactionary podcaster. But even though it wouldn't make sense to have The Daily Bugle be a New York Post-type tabloid in 2019 -- print being on its last legs and all -- it would have been a downright shame if someone other than Simmons had played Jameson. Prior to his Whiplash Oscar win, Simmons gave what is essentially the ultimate comic book movie performance. His Jameson is so broad that he somehow channels an illustrated panel, and yet blends seamlessly into the world around him. I wouldn't want anyone else chomping on that cigar.
Sure, the ending of Far From Home foreshadows a tumultuous stage in the saga of Peter Parker, one that the MCU will have to address in the next Spider-Man movie. That's bad news for him, but it's great news for us if Simmons is along for the ride.