Its a risk they undertake when doing this.
Reasonable would say we should give access to things they don't bother to give access overseas.
However, with the old copyright we established decades ago, legally they still hold the legal copyright, not to mention the complicated 'Creator copyright and distribution copyright ' within Japan's Copyright law (yes you Japan, you mad man).
Tl;dr
They can be a arse and dicc about by not translating or grant access to other regions market, because legally they can be a dicc by holding the rights, unfortunately.
PS. Also different country have different copyright laws.
Length of copyright,
Does it automatic apply upon creation or manual registration,
Types of copyright,
Definition of 'works' classified under copyright.
All in all, its a fucking hassle.
I just had to practice the ' me no see works, never knew works, never feel pain of missing works because it didn't perceived by me' as long as they play the legal dicc move.
We can now feel the old days of 'getting cucked out the final volume of a series because they didn't translate it' again...