No, not likely. MP Soundwave and Thudnercracker were both confirmed via TRU listings before they were actually announced, so I can't imagine they'll switch to Screamer at the last minute. Most of us think Hasbro is doing the "make 'em buy the same toy 8 times" scheme, where they put out everyone but Starscream first to get as many sales as possible, because there are a lot of people who might stop at Starscream if he were coming first. So I expect Sunstorm this year, "Firestorm" (red) next year, "Icestorm" (light blue) the following, "Snotstorm" (beige/light green) after that, Skywarp next, "Captain Fabulous!" (rainbow), and any number of others before they put out Starscream in 2034 for the 50th anniversary.