Previously, the authoritative insider Daniel Richtman reported that the fourth part of "Sonic in Cinema" could get the subtitle Sonic CD, which would hint at a plot related to time travel, since this theme was first touched upon in the game of the same name in 1993.
These rumors spawned expectations among fans for the appearance of Silver the Hedgehog, who is also associated with time travel and possesses psychokinesis. However, Silver first appeared in Sonic the Hedgehog (2006), not in Sonic CD, and now Richtman has confirmed that the character will not appear in the upcoming film either.
So far, there are no official details about the plot of "Sonic 4 in Cinema", so all information should be taken with a grain of skepticism. The premiere of the film is scheduled for March 19, 2027.