The October 7 date is Into the Spider-verse 2.I think that plays a part. At some point in the near future you’ll have too much content from Marvel, Star Wars, Pixar, and Disney animation that will have to overlap. So if Mandalorian Season 3 is running the same time as Moon Knight, at least it will be different days of the week.
Marvel has so much content the next 2 years they could probably drop an episode/movie nearly every week.
2021 Theaters: Black Widow, Shang-Chi, Eternals, Spider-Man 3
2021 D+: Loki, What If, Ms. Marvel, Hawkeye
2022 Theaters: Doctor Strange 2, Thor 4, Black Panther 2, Captain Marvel 2, and Disney has yet to give up their October 7th date that was originally meant for Blade.
2022 D+: She-Hulk, Moon Knight, Secret Invasion, Ironheart, Armor Wars, Guardians Holiday Special
2023 Theaters: Ant-Man 3, Guardians 3, Fantastic 4, Blade, and MAYBE Deadpool.
2023 D+: I Am Groot
So Loki is probably a good show to test the mid-week waters. I wonder if What If follows suit in August.
Other D+ series announced with no date: Wakanda, Echo, and probably a Loki 2.
Other theatrical releases: Morbius and Venom 2 (if one counts the Sonyverse), maybe a Sam Wilson Captain America film, and eventually an X-Men slate of films, and maybe an Eternals 2 if it does well, and maybe a New Avengers or Young Avengers, etc... We know Feige has a plan that spans years and years.
And honorable mention: MODOK now on Hulu; and Hit Monkey to follow suit.