I strongly doubt that, the game would be over already
I bet the info you catched was 4 weeks (in game) since that's ho long the carnations contest is supposed to last. No, i don't remember if the game is in the 2nd or 3rd week of the contest. I think the second, since the 3rd week of the previous year's contest was a 'free use' day. Which i'm positive won't happen in this edition of the contest. You know.. NTR... but i think i'd noticed it didn't happen.
Now, not sure what the plan for the plot are. Maybe the contest will be interrupted before the 4th week in the climax event that crushes the bordello activity once and for all or it will just go through and something will happen later.
In any case i'm positive we will see at the very least Chapter 5. Not impossible a Chapter 6. And let's hope M&J won't go full BaDIK an pull out some bullshit like 'and that was season 1, for season 2 we have...' Spin offs are cool, endless games aren't.