That would make sense in terms that Raszageth being imprisoned in a different place from her peers, her being the last to be handled in an operation headed by Neltharion. But it's not really made explicit either in the shorts or in-game, and the cinematics make it seem like he handled the sealing of the Incarnates himself. Also, why would the other Aspects put Neltharion in such a predicament, to begin with, if they'd already done the job of sealing the others, and why would Raszageth have such a personal beef with Alexstrasza if Neltharion was the person who imprisoned her? The Aspects are kind of defined in Twilight of the Aspects as deriving their power from working as one, so it seems thematically odd that they would leave such a task up to one of their number as opposed to tackling it head-on as a group.
Either way, it seems poorly hashed out to me.