This is linked to the delay caused by SEGA JP's work from home policy. PSO2JP was going to be "upgraded" to the CERO equivalent of M for Mature during this month, but was delayed due to their new content being delayed.
Why does this matter? Well, it means that Episode 6 is the cause of the rating, firstly. Secondly, if our rating was initially supposed to be M because of Episode 6 content, that means that we are indeed getting all of the content.
(that last line is in reference to those who keep saying we aren't going to get the content or catch up to Japan)
(p.s., all your "the game is rated M" arguments just vanished)