Slitherine

I was playing Midway and sunk the three US carriers to the Northeast, but the event never fired. Did I miss a fourth, secret carrier, or is the event bugged?

Will this affect future scenarios in a way where I should replay the battle?

Actually, the number of carriers present in this scenario depends on how many carriers have you sunk in the previous scenario. If you click on the question mark in the secondary objectives, it will show you the reward description which says "you get 200 RP per destroyed carrier". If you destroyed 2 carriers in the previous scenario (as I did), you can't complete this secondary objective. I'm guessing this is some editor limitation as you can't have variable secondary objectives based on previous scenario.

Anyway, the reward is gained per destroyed carrier, so it doesn't matter that you can't complete the secondary objective. Also, from the RP gain point of view, it's better not to destroy all carriers in the previous scenario, because in that scenario you are not rewarded RPs.

Thank you for the response. Wish they had made that clear.