OK, first off, let's state the blindingly obvious - this is a show about yuri. It's called Yuri Bear Storm, the female characters are labelled 'yuri', and there's a literal court that determines what is and is not acceptable yuri. Since Ikuhara is one of those highfalutin directors who includes messages and themes and all that shit in his work, it seems reasonable to guess that we're looking at an examination of the yuri genre and Japanese attitudes towards female homosexuality in general. It's not 100% sure what he'll say about this, but it's clear that he's addressing it.
With that in mind, let's look at the history and origins of yuri as a popular literary genre. Around the early twentieth century, a socioliterary trend called Class S took off. Inspired by the Western concept of romantic friendship, which had been imported via Victorian literature during Meiji Japan's frantic Westernisation, it held that girls should form close, romantic friendships with each other in order to train themselves as proper wives for their future husbands, as part of the 'good wife, wise mother' philosophy brought in to indoctrinate Japanese women as good little baby-factories for the expanding empire. It had a lot of cross-pollination with the legendary Takurazuka Revue founded in 1914, which I'm sure many Ikuhara fans are familiar with. For the uninitiated, the Revue is a musical theatre troupe based on traditional Japanese kabuki, with the big twist that rather than being all-male, the actors are all-female. It's loud, hammy, garish, and hyper-stylised - sound familiar? Anyway, Takurazuka occupies a complex place in Japanese feminism and LGBT rights. It's often viewed as a liberating force, allowing women to escape the bounds of their gender, but while the actors are women, the whole spectacle is very male-controlled - the directors and backstage staff heavily skew towards men, and the original creator of the Revue, Ichizo Kobayashi, was a wealthy industrialist (the president of the Hankyu Railway company, in fact, which is why the Revue's named after the Hankyu Takurazuka line in Osaka and the actresses are all employees of Hankyu Railway) who created it as a training ground for housewives in-keeping with the Meiji 'good wife, wise mother' ideal.
Class S had a major impact on Japanese attitudes to lesbians. It meant that same-sex relationships between girls were acceptable if they didn't go too far, and if they were stepping stones on the path to a proper, heterosexual marriage. Adult lesbians were shunned and treated as immature/in need of a good hard dicking. This was reflected in Japanese lesbian fiction, yuri, where two options were traditionally presented to the main characters. One is 'Story A', a light, fluffy romance juuust this side of a close friendship where two girls like each other, discover they like each other... and then the final curtain slams down like a guillotine before the relationship can develop beyond holding hands, gazing soulfully into each other's eyes, and maybe a kiss if they're lucky. More sexual lesbian relationships tend to end in death or some other permanent, tragic separation, as the girls receive karmic retribution for violating society's norms, in much the same way as Hays Code-era crime movies showed gangsters being cool and awesome for almost their whole runtime before they were abruptly punished for their crimes in the last few minutes.
Now let's look at how this applies to Yuri Bear Storm. There's a clear contrast between the bears and the humans set up here. Kureha and Sumika's relationship is extremely chaste and desexualised, but still faces systemic opposition. The girls are dwarfed by enormous buildings and literally walled into their society. Their world is bright and colourful, but very regular and ordered, with a miasma of paranoia and oppression. The bears, on the other hand, are free and enthusiastically, aggressively sexual - they're responsible for 90% minimum of the fanservice and sexual imagery, and eating is an obvious metaphor for sex (rape, in fact). As opposed to the tame, Story A yuri of the human world, they're the predatory 'psycho lesbian' villain stereotype of innumerable Japanese and Western shows. They present a threat that can only be fought by conformity with the social order that controls Kureha and Sumika's lives. Even the bears aren't free, though - they're subordinate to the Court of Severance, the only men in the cast so far, who decide what is and is not acceptably sexy, beautiful, and cool yuri. Remember what I said about the organisation and purpose of the Takarazuka Revue? In fact, if Ikuhara's being self-aware, this might even be commentary on the fact that he, a guy, is directing a yuri show. "Will you be invisible? Or will you eat humans?" is a really telling line - the arbiters of yuri are asking the bears to choose between what is socially acceptable (tame, desexualised same-sex relationships) and unleashing their lust in an aggressive, blatant, and destructive manner. I wouldn't be surprised if the goal here is to preach a middle ground that goes against what either the Court of Severance or the human world will allow - a stable, loving, and openly sexual lesbian relationship. Certainly, that's what the opening seems to champion, with Ginko, Kureha, and Lulu ending it leaning against each other in a happy, naked heap after expressing their mutual affection with a string of kisses.
Basically, the evidence so far seems to suggest that Ikuhara's purpose here is to say 'yo, Japan, your attitude to lesbians is kind of fucked up and restrictive - let the girls have their fun, why don't you?'
