In case you didn't catch the end of Far From Home, Mysterio was a typical duplicitous villain. His statements regarding the multiverse were just a rouse to get Fury and Spider-Man to accept his SFX-driven persona. There have been no (legitimate) statements regarding 199,999's place in the greater multiverse that 616 exists within. We'll have to wait until Doctor Strange 2 releases to (hopefully) get answers to these questions.