One thing that Disney's Hawkeye has made clear is just how many Marvel fans love Kate Bishop and Yelena Belova. In fact, there is a call to see these two heroines in a romantic relationship, as countless fans have been shipping them online.
This is not surprising. The MCU is starved for queer representation while Kate and Yelena have a natural rapport that frequently seems to border on the flirtatious. Also, while casual fans might not know this, both characters are on the LGBTQIA+ spectrum. However, because of their very specific identities, a relationship between them would not work.
Gender and sexuality each exist on a spectrum. Unfortunately, while Disney will trot out occasional token characters to appeal to fans, the company has so far refused to highlight any meaningful, nuanced stories or characters that deviate from their very dated sense of cis-heteronormativity. This is not only tragic, but also ironic, considering both Kate and Yelena would almost certainly scoff at this attitude.
Kate Bishop was created by Allen Heinberg and Jim Cheung, debuting in 2005's Young Avengers #1, a series that proudly introduced the same-sex relationship between Hulkling and Wiccan at a time when such representation was almost nonexistent in mainstream comics. After the initial Young Avengers comic ended, writer Kieron Gillen and artist Jamie McKelvie launched a reboot in 2013, featuring a team of teenaged heroes with far more diverse sexualities and gender identities. In the final issue, Kate takes a moment where she pauses to ask if she is the only member of the team who is straight. Her teammate America Chavez turns to her and says, "Princess. I've seen the way you look at me. You're not that straight."
Obviously, this line does not supersede Kate's understanding of herself as a person, but it also should not be dismissed. Neither sexuality nor gender is static, and in a series that is dedicated to young heroes exploring and embracing both, concluding the series with this exchange opens new doors for the character. Of course, just because Kate was checking out her female colleague does not mean anything definitively for them as a potential couple nor does it fit Kate into a narrow definition. People discover new aspects about their identities and attractions throughout their lives. Some possibilities to consider are that Kate could be bisexual, heteroflexible, biromantic, or could be questioning her sexuality.
Yelena Belova is a very different sort of character and was created by writer Devin Grayson and artist J. G. Jones, debuting in 1999's Inhumans #5. Grayson has stated that she considers Yelena to be asexual and does not see her having romantic relationships like Natasha does. These ideas were reaffirmed in the comic Black Widow: Pale Little Spider (by Greg Rucka and Igor Kordey) when a professional dominatrix flirted with Yelena, assuming her to be a lesbian. Yelena responded "I'm not a lesbian. I'm not...anything."
Those unfamiliar with LGBTQIA+ dynamics may not be aware of everything that the acronym stands for, but the A is usually representative of people who are asexual (ace), aromantic (aro), or agender. Such folk are seldom given proper representation, but Marvel has two asexual characters (the other being the new Wasp, Nadia van Dyne). Yelena's statement to the dominatrix shows that she has found conventional words about attraction and relationship dynamics do not reflect her lived experiences.
Ace and aro people can still form meaningful loving relationships. Aces might seek romantic relationships, while aros might enjoy sex. However, someone who is both ace and aro is more likely to find fulfillment in the love they have with friends and found family - something the MCU's Yelena demonstrates with the emphasis she puts on the importance of her family above all else.
Of course, it is still okay to ship Kate and Yelena. Everyone should be able to enjoy fandoms in their own way. However, these two are not the queer romantic couple that the MCU has been waiting for, and it is long overdue to allow ace and aro fans to finally see themselves represented in a superhero franchise.