Even though the MCU has been around for nearly a decade and a half now, they're still finding new and innovative ways to break the repetitive mold that large movie universes tend to fit into. One such way was the MCU's first attempt at a holiday special during the airing of the Hawkeye series on Disney+. The series might not technically count as a "special" since it was a 6-episode miniseries. Still, Kevin Feige has confirmed that Hawkeye is meant to be a holiday show that he wants fans and audiences to return to every year during the holidays.
In that light, and due to Hawkeye's renowned success, the MCU has decided to lean full-tilt into the "holiday specials" concept in order to keep mixing things up and give fans extra doses of superhero content sprinkled in throughout the year. While they might have missed an opportunity by not making a Captain America 4th of July special, the two specials that have been confirmed are the Werewolf by Night Halloween special and the Guardians of the Galaxy Christmas special. Marvel fans can hardly decide which one they're more hyped for.
Werewolf by Night Halloween Special
While Hawkeye was meant to be the MCU's first true holiday installment, this particular special will be the first of its kind to air on Halloween. We haven't been given much information on what to expect from the special other than its Halloween release date. But from the small bits we have gathered, it is pretty much confirmed that the MCU will be introducing not just werewolves but also vampires during the special. The pieces of information that point to that include Blade being cast and appearing in the MCU (Mahershala Ali's voice came at the end of Eternals). There have been recent reports that Blade will be appearing in the Werewolf by Night special. In the comics, werewolves and vampires are created due to magic from the Darkhold (already seen in WandaVision). The Darkhold is rumored to make another appearance in the upcoming Doctor Strange 2.
A less confirmed piece of info (more a theory) is that Moon Knight can be seen pummeling a creature to death in the trailer for his upcoming Disney+ series. Some fans have speculated that this creature is, in fact, a werewolf. Perhaps not Werewolf by Night, but the 'moon' background of the show would make that idea quite plausible. While all of this ramps up the idea of werewolves vs. vampires, it doesn't answer how Werewolf by Night fits into the MCU or how Blade or Moon Knight are related. The theorized answer is that Werewolf by Night will be joining an MCU crew called the "Midnight Sons," an Avenger-equivalent team that takes on darker, more mystical threats in the Marvel Universe. Members include Blade, Moon Knight, Black Knight, and Werewolf by Night, all characters that the MCU has been teasing and leading up to. With all of that said, despite a lot of it being speculation, it's safe to say that fans are truly hyped for this newcomer.
Guardians of the Galaxy Christmas Special
Hawkeye might reign supreme as the first MCU holiday series, but Guardians of the Galaxy will be the first to get a proper Christmas special when it airs this coming December. While fans have gotten little information about the Werewolf by Night plot, they've unfortunately gotten even less concerning the GotG Christmas special. The main reason behind this is quite simple. At the end of Avengers: Endgame, Thor goes off with the Guardians to explore the universe with his new band of merry pals. As such, director of the GotG Christmas Special, James Gunn, has confirmed that the events of the special will be taking place after the events of the upcoming Thor 4 and will be a precursor to the even further upcoming Guardians of the Galaxy 3.
The MCU is super secretive about any project that hasn't been released (Thor 4). Since the Guardians will probably be making some sort of appearance in that film, it's very unlikely that fans will be getting much information on the Christmas special until after Thor 4 has been released in theaters. Nevertheless, fans are still properly hyped for the Christmas special. Guardians of the Galaxy are some of the MCU's most beloved and hysterical characters, and we have gotten very little screen time with them since their second standalone feature back in 2017.
In conclusion, Werewolf by Night probably sits atop the hype train at this present time due to the implications of the Midnight Sons being established and the lack of information on the GotG Christmas special. However, that could quickly flip on its side after Thor 4 premieres and fans start to receive more news on the universes' most lovable band of misfits. Quick question -- do other planets celebrate Christmas?