This is an odd rumor for him to confirm, given that the original report was that the character would be the series lead, a role that ultimately fell to Dr. Octopus.
Allow Slott (via MTV Geek) to explain:
Here’s his statement, for those who can’t view the video:
“I wish to apologize; I did a horrible prank. That prank was, I put a tweet up online on a midnight on a Saturday and made it look like it was a direct message to my artist Ryan Stegman that hinted that a character Miguel might be the new Superior Spider-Man. I am very sorry; it was a prank, it was a trick, and all of these poor fans of Spider-Man 2099 were so certain that Spider-Man 2099 was going to be the Superior Spider-Man. This is not a trick, this is not a prank–you will see Miguel O’Hara in Superior Spider-Man.”