J line is honestly a non issue. If their company refuses they cans simply choose to graduate and go to Korea just like Juri did when she joined rocket punch. Hitomi for one has clearly expressed her interest in rejoining Iz*One. It's late at night so I won't look for the link but in a very recent radio show she said that she has thoughts of continuing with Iz*One and that she even went to meet up with Minju and a staff member in Jeju. She was also the one who was bursting into tears at the airport when Iz*One disbanded and they were heading back to Japan.
As for Nako, her intentions are the only ones I am uncertain about because she hasn't really said much of anything about the situation as far as I know. But if the article is true when it says all the members are willing, chances are that she wants to return as well.
The only issue with J-line is Sakura who may already be signed with HYBE considering how she rushed her graduation. If we're lucky maybe she hasn't signed her contract with them yet or if she has maybe they are one of the Korean companies in discussion of letting her participate.
And since someone asked, J-line are not all under the same Japanese label. Most of the AKB48 groups belong to different companies now.
This is what I found on AKB48 reddit:
"All the 48G in Japan are owned by different companies:
- AKB is owned by DH
- SKE is owned by Zest
- NMB is owned by Showtitle
- HKT is owned by Mercury
- NGT is owned by Flora
- STU is owned by Setouchi Co. Ltd.
DH~~, Mercury, and Flora are~~ is owned by Vernalossom. ~~The remaining probably are not and it's possible that Vernalossom has a minority stake in the other companies.~~ Mercury and Flora are under Sproot as mentioned [here](https://old.reddit.com/r/AKB48…t_rescheduled_to/h2530j0/)
Outside of Japan, the international 48G are managed by Vernalossom
But again, what their office wants is irrelevant because thdy can simply graduate. It's just up to the girl.
And well, since I was already on reddit I decided to look for the link where Hitomi recently mentions wanting to continue Iz*One for those curious: