Given the nature of comic book movies right now, from Doctor Strange in the Multiverse of Madness to The Flash, with stops at TV shows like The Flash (different one) and WandaVision, when the news broke today that Jamie Foxx is considering a return to the Spider-Man franchise it was easy to assume it was all part of a multiverse story. If it isn't, though, then what it means is that Kevin Feige and Marvel Studios are more open to taking some of the old casting choices from previous regimes and moving forward with them? It isn't necessarily a crazy idea.
When JK Simmons first appeared as J. Jonah Jameson, very few people immediately thought that he was from the Sam Raimi movies and thus confirmation of a multiverse. His performance in those films was universally beloved, and it was accepted by most (although certainly not all) people in the audience that it was just a case of Simmons having proved himself more or less irreplaceable.
That isn't the case with Electro, necessarily -- Foxx's performance was polarizing, and The Amazing Spider-Man 2 was not widely liked. But Foxx is also an Academy Award-winning actor. So the question then becomes whether this is a multiversal crossover with an unpopular movie, or simply reusing the guy who the studio had cast for the part not that many years ago.
If it's the latter, then some fans are already wondering whether that could mean a return for actors like Vincent D'Onofrio, who played The Kingpin in Daredevil on Netflix. There is a perception that there are rights issues that are an entanglement to reusing the exact shows as previously produced, in a way that other Marvel productions created with Disney-owned ABC or Hulu would not.
That might be something they coudl work around, by simply casting one or two standout actors as the new version of the same character in the MCU, and then establishing through story or other casting that it isn't "the same" world.
This is kind of the way Brandon Routh's Superman in "Crisis on Infinite Earths" was clearly the same guy from Superman Returns but, with a different costume and no time to dig into his backstory, there's obvious deniability in case anybody at Warner Bros. Studios didn't like the idea.
So far, there's a whole lot of people waiting to hear whether Marvel might pick up Charlie Cox, Jon Bernthal, or other beloved actors from the Marvel-Netflix shows to bring their characters to Disney+. Only time will tell.