The Flash is quite familiar with bringing characters back from the dead, or at least bringing back actors whose characters are dead, if not necessarily bringing corpses back to life. As Barry's mission in Season 3 reverts to altering a future in which Iris is murdered by Savitar, the Scarlet Speedster will apparently once again run into his old colleague and quasi-rival Eddie Thawne. Or, more likely, some non-original version of Eddie Thawne. The news was revealed by actor Rick Cosnett himself.
Okay, so technically, Rick Cosnett doesn't flat-out say that Eddie Thawne is returning, only that he, the actor, is. Which unfortunately does allow for The Flash to bring up a distant cousin, Freddy Thawne, or something along those lines. But the fact that Cosnett is returning to the superhero drama for an arc tied to Iris' safety and survival, it's likely that Eddie proper will be the one that audiences connect with.
So the question then shifts over to which Earth and which timeline this upcoming Eddie will hail from. The former CCPD detective first left the narrative when he sacrificed himself at the end of Season 1, totally messing with the Thawne bloodline. And he returned in Season 2 when Flash went back in time to con some advice out of Eobard Thawne/Faux Harrison Wells and then found himself a target of those dreaded Time Wraiths. Even though Barry is currently facing a problem that occurs in the future, he is always looking into the past for answers, so another Flashback Eddie is a possibility.
Or, with all that Barry has gotten help from Earth-3's Jay Garrick, perhaps that other-dimensional location will be where Eddie Thawne reappears, similar to how Mark Hamill's Trickster showed up in the mid-year finale. Eddie could also show up as a hallucination of Barry's (or another character), something that Arrow's Oliver Queen knows a lot about. And even though the plotline is moving away from the Flashpoint arc, Eddie could always be another loose thread from Barry's timeline-switcheroo, still alive and walking around Earth-1. However it goes, it'll probably be exciting, especially if we get to see Rick Cosnett get angry.
Sadly, there's no telling when Rick Cosnett will return to The Flash, as his tweet wasn't specific about such things. Though we can infer that Spencer A. Harvey and Lloyd Harvey will be the filmmaking duo directing the episode he's involved with, so whenever The CW puts out releases with that information, better connections can be made.
The Flash finally returns to The CW for the remainder of Season 3 on Tuesday, January 24, at 8:00 p.m. ET. To see what else is heading to the small screen in the future, head to our midseason premiere schedule.