Tbh I don't really feel like it makes sense for Hell to calm down about Heaven completely just based on the knowledge that redemption is now possible.

From what we saw earlier when Vox was provoking them one of the things he appealed to was the sinners not wanting to actually change everything about themselves in order to get into Heaven

so on that front Pentious being redeemed wouldn't make a difference to the people who wanted to attack simply to get their hands on the goods of Heaven,

and in regards to the sinners that were acting out of fear well why should his redemption calm that down either? the person who gave the orders as well as every soldier who carried them out are all still very much in power

literally no change has been made to Heaven's system and given how Pentious is one person who has been redeemed in years and Heaven thought they had to kill thousands of sinners in every extermination

to not fear them becoming a threat so well why would they think his redemption is a viable solution that guarantees Heaven will never attack them again?

and in regards to Emily helping save them during Vox's Rampage well why would that matter either? Emily had nothing to do with them in the first place so its not proof of any meaningful change from Heaven,

now if Sera had actually been the one to do it after publicly taking responsibility for the order during Vox's rally then I could kinda get it as it would be the person who caused it showing strong hard proof that she's devoted to change

and not being a threat to them anymore by actually helping save the city when she could have let them die but having Emily do it literally means nothing story wise tbh so I feel like the show missed a trick here,

or even if the show's ending montage had made it clear Heaven's leadership system had changed somehow and wasn't literally just staying the same with everything falling on Sera's shoulders and her word still being law

that would at least be something but as it is Hell calming down when nothing has really changed and Heaven hasn't really proven it isn't still a possible threat just seems weird and rushed to me.