He's not gotten a long contract because the team doesn't know how he'll fit, so it's low cost, high reward, and secondly, even if they thought he was such a gem, they are prohibited by the rules of free agency. He'll come in on a one-year deal because it gets him past the entry-level deal quicker, as there is no incentive for him to come over, toil for a few years on an entry-level at his age when he could stay in Russia to make more during his upcoming prime. He wouldn't come over unless he knew he was a sure thing or they gave him a short window to prove it before he could pack it back up to Russia.
I think the hype is realistically only aimed at the fact that he's basically a free prospect that could win a depth defenseman roster spot next year. He's 26, but defensemen develop later, and he had a really good season in the KHL. A free asset is nice as always, and anything he produces beyond the AHL is bonus.