Interestingly, Shamook is actually a deep fake researcher, and it seems like his YouTube content has become more of a byproduct of his research. So at first this hiring feels like Lucasfilm hired a fan with a interesting hobby, but Shamook is actually a professional in his field, to my understanding.
It’s possible he’ll be doing work for future Star Wars projects down the road (him improving older effects is possible but I doubt it), I think they’ve brought him on now for the new Indiana Jones film. There will probably be flashbacks to young Indy, so I imagine Shamook will be working with ILM to make the effect look as believable as possible. I’m pretty excited to see what they’ll cook up.