Marvel Studios is currently at a point where they’re open to branching-out various characters with their own Disney+ shows or even giving them their own films. A good example is Anthony Mackie leading Captain America 4 after playing a sidekick for years and then landing his own series with The Falcon & The Winter Soldier.
Could we see that with David Harbour’s Red Guardian?
Black Widow director Cate Shortland believes that Red Guardian deserves his own film while speaking with The Wrap. She previously said she’d return for a hypothetical Black Widow 2, that could be led by other characters (Florence Pugh’s Yelena is a given).
“Sometimes — not sometimes — often I would be crying with laughter. And there was so much good stuff that didn’t end up in the film. But I think that’s why Red Guardian needs his own movie. Because it will be so funny,” the filmmaker told The Wrap as she champions the idea of a Red Guardian spinoff film.
After mentioning to Collider that he’s had early talks with Marvel about reprising the role, David Harbour mentioned to The Wrap he is game for a Red Guardian project if Marvel decided to make it.
“People want to see more of this character, I would love to give people more. And I’m glad he’s alive at the end of the movie too,” David Harbour said when asked if he’d want to reprise the role in a series or movie.
Clearly, there is more you could do with Red Guardian because in the comics he leads his own team, Winter Guard (made up of other Russian Marvel characters), and allows him to do his own side adventures outside of the Black Wdow franchise. Darkstar, Ursa Major, Red Widow, Vostok, Perun, Crimson Dynamo, Fantasma, Sibercat, Powersurge, and Chernobog could end up being members of the Winter Guard roster led by The Red Guardian.

Yelena briefly calls Alexei, Crimson Dynamo, an Iron Man villain and member of Winter Guard.
BLACK WIDOW – In Black Widow, Natasha Romanoff confronts the darker parts of her ledger when a dangerous conspiracy with ties to her past arises. Pursued by a force that will stop at nothing to bring her down, Natasha must deal with her history as a spy and the broken relationships left in her wake long before she became an Avenger. Directed by Cate Shortland and produced by Kevin Feige, the movie stars Scarlett Johansson reprising her role as Natasha Romanoff. Florence Pugh stars as Yelena Belova, David Harbour as Alexei Shostakov aka Red Guardian, and Rachel Weisz as Melina Vostokoff.
SOURCE: THE WRAP