The Flash season 7, episode 14 was missing Barry Allen and Iris West-Allen almost for the entire episode. Wrapping up its New Forces storyline means there's more room to explore other storylines in the final episodes of The Flash season 7, given there's only a few episodes left before the season wraps up. Due to the pandemic, The Flash season 7 only had 18 episodes filmed, meaning this will be the shortest one for the Arrowverse drama yet.
However, unlike the New Forces saga, the upcoming Godspeed storyline will be much shorter since The Flash season 7 has been doing "Interlude" episodes, including Cisco Ramon's big exit. In episode 14, "Rayo de Luz," the story revolved around Allegra Garcia, as her cousin Esperanza, a.k.a. Ultraviolet, came back into the picture. While that was going on, Barry and Iris were mostly absent, with the former explaining at the start of the episode that he and Iris were going on a vacation. Even though Barry showed up briefly at the end to get caught up on what Team Flash had been up to, why were Iris (who wasn't even in one scene this week) and Barry not in episode 14's core story?
Despite Grant Gustin and Candice Patton being The Flash's two leads, this sort of absence is something that has been intentional, as revealed by showrunner Eric Wallace. In a recent interview with Insider, Wallace spoke about the benefits of having such a big cast that allows various episodes per season to focus more on the supporting members. With the showrunner's comments about how exhausting a production schedule like The Flash can be, "Rayo de Luz" allowed Gustin and Patton to take a break. While the story had them go on a vacation, it allowed someone like Allegra, who joined the team in The Flash season 6, to have her story further explored.
Even though it can certainly be a throw-off to viewers, it's important to remember the amount of work that goes into filming a big TV show like The Flash. They film for at least nine months per year since the series regulars normally shoot 20 episodes or more. The Flash season 7 also had the challenge of filming during a pandemic, which is certainly physically and mentally challenging. Even before the pandemic, episode 14 is similar to The Flash season 6 episode "Kiss Kiss Breach Breach," which highlighted Cisco while Iris and Barry went on a trip before Crisis on Infinite Earths. The Flash season 7, episode 14, "Rayo de Luz" was the latest installment to focus more on one of the newer characters.
Both Chester and Cecile have had single episodes where their characters were fleshed out and given more layers. This benefits the show, especially after Cisco and Harrison, two original cast members, ended their runs as series regulars ahead of The Flash season 8. If The Flash didn't allow newer characters to grow and have backstories, it would make them one-dimensional, which wouldn't make for good television. With four episodes remaining in The Flash season 7, it's safe to say Barry and Iris will be at the forefront, especially as their future children, XS and Impulse, will show up as part of the Godspeed storyline.