It could be that the author added ea for 3 chapters Together then the total wait is 16 days
Lemme explain it will th an example
You updated 3 chapters today both with ea
Then the first chapter will be free on May 8
And the second one on 15 then the third one will be free on 22 so if you used gems and unlocked the first two chapters today (assuming today is may 1) then the third chapter would be available for free on May 22 which will be 21 days from now.
So this screenshot was shared just to spread hate against ea and show its negative side