There is not a lot of details about it. Idk if it’s gonna be simulcast or not. I would assume if it was simcast it would be released in Japanese first. Also I don’t think Netflix has the rights or came to an agreement for the arcs in between Marineford and Egghead Island. I’m sure they are working on it since they got the rights to Egghead. Most of the articles said Netflix has gone all in on One Piece and anime in general. Hope this helps sorry for the lack of answers
Simulcast as in same time as it airs in Japan? Bit wild for the world. Different timezones and licences. Did the announcement mention where. I wouldn't think a lot of places had one piece.
Netflix has gotten the rights for some week-to-week new episode releases for foreign shows (The Uncanny Counter, etc.), including Anime like Uncle From Another World. For the "new episodes weekly" anime they've had it has all been sub only upon release to deal with the added delay and rights management of getting the dub versions. I'm not sure if this is going to be exactly the same but Netflix has been trying out the simultaneous release model for a bit now.