Thinking about "AU Where Irina Lives" makes me think of "AU Where Yuna Dies"
And looking at this principally through the lens of how it would impact Shane... I think it would absolutely devastate him not just personally but also professionally. Like the sense I get from the show is that hockey is very much Shane and Yuna's Thing, and David is very supportive but his primary role was funding everything. He also strikes me as being a bit more of a "wife guy" than a "son guy" if that makes sense.
So I think if Yuna died when Shane was 12, I think David would grieve intensely. In my head Yuna wouldn't die by suicide but rather illness, and little Shane would be in denial of what was happening until she passed. Like she would go to the hospital and Shane would be like "Whatever it's fine, Mom goes to the hospital a lot, I'm used to it" and then he would be told she had passed away and he would be completely blindsided by it. If she did die suddenly by accident or suicide, Shane would be even more shocked and blame himself for it irrationally. If she hadn't been tired from driving him to practice she wouldn't have gotten in an accident, if he had been less busy he would've noticed she was struggling, if he wasn't bullied so much she would've been less stressed, etc.
I think hockey was so much a Shane and Yuna Thing he would be unable to play it for a while because it would make him overwhelmingly sad and Shane Can't Process Those Emotions. And I don't think David would push him, either. I think David would be like "You don't have to play if you don't want to" and be very pragmatic about it, since Shane was right at the age when hockey started to become Very Competitive and the future pros start getting sifted out from the kids who are just having fun, and if Shane wants to take a step back from hockey then that's fine and he can focus more on academics and preparing for high school.
It takes a year or two for Shane and David to fully realize that no, hockey is Shane's Talent and nothing can replace that, and Shane gets really serious about hockey again in high school, but at that point he's missed two years of competitive play and he has the feeling of constantly playing catch up and having to prove himself. He also doesn't have Yuna in the background advocating for him and networking and smoothing things over- David is busy at work and Shane is being driven to practice and games by a baby sitter or his teammates' parents, it's more difficult for him to get an agent, he misses out on some opportunities that Yuna would've done research to find and the leg work to enroll him in. In canon Shane knows he's the best and is frustrated that he constantly has to prove it over and over again, and I think that would be even more magnified in this universe, because Shane kind of has to prove it to himself as well, and any loss feels like he's letting down his mom's memory. Shane playing with his mom's name on his stick...
I think he'd still get drafted when he was 18, maybe even as a first round pick, but maybe not second overall. All the biases people have are weighing against him, and he had a slightly spotty record in juniors, and he doesn't have the best agent etc. So he enters his rookie year with a massive chip on his shoulder and A Lot To Prove and just comes roaring out the gate onto the ice, just absolutely tearing it up and playing every game like it's the playoffs.
And Ilya is even more blindsided by Shane, where this random guy who introduced himself at juniors and went 27th in the draft is just absolutely humiliating everyone he plays against and plays against Ilya with a ferocity no one else can match and Ilya is extremely horny about it.
