Crisis on Infinite Earths executive producer Marc Guggenheim has explained why Barry Allen didn't battle Reverse-Flash during the crossover event. The much-anticipated Crisis on Infinite Earths ended this week, forever changing the Arrowverse. The event made good on its promise to feature numerous cameos, including one fans are still raving about.

It's amazing to think about, but Crisis on Infinite Earths has technically been alluded to since The Flash premiered in 2014. The infamous newspaper headline, "Flash missing, vanishes in crisis" has been a point of mystery. It returned in season 5, which had Barry's daughter Nora travel back in time to try and prevent her father from vanishing. At the center of this was Eobard Thawne, the Reverse-Flash. Thawne was the central antagonist in season one, and appeared quite a few times afterward, including Legends of Tomorrow and the Crisis on Earth-X event. The newspaper stated Barry to vanish while fighting Thawne, so fans have been highly anticipating this encounter. However, Crisis on Infinite Earths has come and gone, with no sign of Thawne. Now, fans know why.

Related: Arrowverse's New Multiverse Revealed: Which Shows Are On What Earths

In an interview with TVLine, producer Marc Guggenheim was asked about Reverse-Flash's lack of appearing in Crisis on Infinite Earths, despite the newspaper. According to the producer, it comes down to the Crisis showrunners not being "beholden" to that newspaper headline.

"I guess what it really comes down to is not being beholden to a headline from six years ago that was not written by any of the showrunners involved in the crossover. A lot of things drive our stories, and a lot of things determine what choices we make….. To me, tracking toward a headline written six years ago is literally the definition of 'the cart driving the horse.' We’ve had Reverse-Flash so prominent in the Arrowverse over the years, including in last year’s crossover and the crossover before that…. I love the character and I love Tom [Cavanagh] as a person, and I certainly love Matt Letscher’s version, but you have to make choices."

Some fans might agree with Guggenheim's reasoning. Crisis on Infinite Earths is already jam-packed with the Anti-Monitor storyline. It would have probably been difficult to squeeze in a notable Thawne encounter. On the other hand, many are disappointed, since the Crisis did not feature that heated conflict between longtime enemies. In the last episode of The Flash season 5, Thawne even tells Barry, "See you in our next crisis." Understandably, fans feel misled, because they assumed the character would appear.

The CW recently released The Flash's season 6 midseason premiere teaser. It seems Barry's relationship with Iris might take a troubling turn post-Crisis. A new terrorist organization looks to make its debut. Unfortunately for Thawne fans, Reverse-Flash is nowhere to be seen. Still, Thawne was set loose in season 5, so it's quite possible he will cause trouble for team Flash in the future. Something to keep in mind, though, is Crisis on Infinite Earths did change things, so it's possible Thawne's escape was altered in some way. It remains to be seen, but more likely than not, Thawne will get to battle Barry again. The Flash season 6 returns Tuesday, February 4.

Next: Arrowverse's Official Justice League Team Revealed In Crisis On Infinite Earths

Source: TVLine