Jessica Jones and Agent Carter are the only female lead characters in the MCU so far, the original Avengers/Guardians line ups each just had one woman out of five or six heroes and we've had to wait until the 10th year of the MCU to get a female led film with Captain Marvel. Compare that to Thor, Cap, Iron Man, Hulk, Spidey, Dr Strange, Ant-Man, Black Panther, Daredevil, Luke Cage, Iron Fist etc plus mostly male led Avengers/Guardians/Defenders within the first ten years and it does start to look like a poor showing gender equality wise.
Part of the problem was lack of willingness to bet on a female/minority lead before Wonder Woman/Black Panther. Hopefully that's going to change now.
I do think another factor behind the MCU's limited diversity is that it's a reflection of the lack of diversity in the comics. Most major 616/Ultimate Marvel heroes are male - definitely the vast majority of characters that have had their own comic - and that's something that's been built up over almost 60 years so it can't be fixed overnight. There aren't as many major female/minority characters to adapt - especially outside of the X-Men - and a lot of female heroes are legacy characters (e.g. She-Hulk, Spider-Woman, Kamala Khan, Riri Williams, Shuri as Black Panther), aren't the main heroes of the stories they appear in (e.g. Valkyrie, Sif, Clea, Sharon Carter) or are fairly obscure for non-comic buffs (e.g. Spectrum, America Chavez, Mockingbird, Quake, Elsa Bloodstone etc).
With that in mind I definitely think trying to make half the MCU heroes female is ambitious (and I'm pretty sure he must have the X-Men in mind for meeting that target) but Feige knows what he's doing in terms of respecting the source material and great storytelling and I hope he pulls it off.