I'm kinda indifferent on this one. Cowboy Bebop might have a change. Smaller crew, so they could afford a cast. This doesn't seem to have the budget for even that. Kinda funny given that OP is more popular than CB. I hope it's good. I expect it to be bad.
Budget is $10 million per episode, $100 million for the season. I think only the later seasons of the Crown and Stranger Things have cost more for Netflix
This is the right direction, get relative unknowns who fit the part best and would be willing to be part of a project that could last a decade or more if successful. Just getting celebrities would be a mistake. That's what Game of Thrones did right with casting.
Means more money for production as well.
I could see some bigger names being thrown into the roles of Roger, Shanks, Mihawk etc. Or later villains like Crocodile, Doflamingo etc who will only have brief appearances now and then but are still a big role
Best celebrity fan cast I've heard of is Ken Jeong for Buggy and Jeff Goldblum for Kizaru