Maybe you can. But it's precisely why Polar can't and won't.
What, in practical terms, (does compromising by going back on our word in my view, but I accept that you'll think it's little details not worth staying true to) prolonging the war for a 'short period' accomplish? I agree that we should have made sure everyone on our side know first before the announcement was posted. But beyond that, how exactly does it help anyone? TOP and IRON would still be at war with CnG whether Polar is at peace with PC and \m/ or not. Peace on the other fronts of the war still need to be resolved by the alliances actually on those fronts.
The only way this would have mattered would be if TOP and IRON was planning to post their declaration after \m/ communicated its desire to end this war. In that case a notification that the war have ended at the core could/might halt their entry. But since the two events occurred at roughly the same time, whether the peace declaration was posted 45 minutes later or 2 days later doesn't change the fact that TOP/IRON are now at war, while \m/ have accepted to end the war with Polar. Not unless, again, Polaris was to go back on her word.
In short you're arguing about something that have absolutely zero bearing on the actual outcomes of Polar and \m/ reaching peace.