Hollanov is literally the perfect ship for non-traditional alpha/beta/omega dynamics and people are STILL writing shane as an omega and ilya as an alpha? No shade to anyone who is doing so but there's SO much potential out there for other dynamics.
Alpha/Alpha: Makes sense, since they're both professional athletes. Fork found in kitchen. BUT it lends itself to another layer in their already complicated relationship. The outside world (cough cough the NHL) doesn't want them to date not just because they are both men, and because they are rivals according to all news sources, but because alpha/alpha romance is not the norm and looked down upon as alpha/omega or even alpha/beta partnerships are the norm. Also, Shane would feel even more conflicted/comfortable with bottoming, especially if ruts are involved.
Alpha/Beta: See above (on the norms point), but also the potential for miscommunication!!! One of them is not a part of the other's world- they don't get heats or ruts, they don't smell people the second they see them, they don't have the same urge to mark, or court, or the number of other things alphas do. The relationship that made an eight year miscommunication trope work is literally the perfect ship to add another even more devastating layer on top of it.
Beta/Beta: Both of them would not only stick out in the league more as alphas are more common in professional sports, it would make their public "rivalry" even more devastating. Media has a tendency to pit similar people (especially minorities) against each other (you know after hollanov because public, any time they play against the admirals, the announcers mention that they are all gay and pit them against each other). It would give them something else they in common with the other, in addtion to being one of the only queer people in the NHL, they're also some of the only betas! They understand each other better than anyone else in the league ever could! Also, a whirlwind of miscommunication tropes as the other alphas fight with each other over Stupid Alpha Things (TM) and they make heart eyes at each other because that could never be them.
Beta/Omega: Neither of them would be particularly accepted by the league as non-alphas, but the extra tension of one of them having to hide their secondary gender. See the alpha/beta point above about one of them also not being a part of the other's world, not understanding heats, scenting, courtship, etc. I think this would be especially potent for angst fics... the omega in the relationship needing help in a specific way (heats, calming scenting, etc) and the other being at a loss but wanting to do something to help but having no intuitive guide. Anything that forces hollanov to communicate is chef's kiss in my eyes.
Omega/omega: The best of the bunch in my eyes. Not only are they not accepted the NHL in any way, not only does their secret become that more scandalous and dangerous should it come out, but it completely puts a new spin on queer people and secondary gender. Like, queer couples that fall into acceptable secondary gender pairings would be more accepted than those that don't, so everything that already exists within hollanov just gets heightened. It also adds I think a layer of commentary that would get thrown around by anyone in the heated rivalry universe who talks about it after hollanov becomes publicly gay- as someone has to top in the relationship... and omegas are supposed to bottom... all news outlets wouldn't know how to spin the narrative in a way that reinforces existing stereotypes about secondary genders because this omega/omega relationship defies all expectations about what omegas are supposed to do (have children, bottom, be nurturing, be kind, etc) and what roles they can play in society, especially because shane and ilya are so dominant within the hockey space.
Also, the potential for sexually explicit fics within all of these dynamics is literally only limited by what our big beautiful brains can come up with. I just want to see more experimentation within the omegaverse because hollanov is SUCH a perfect example of a complicated relationship and i want to see other people play with it more.