How do we know any of this? Are you suggesting that Gunn doesn't have a plan or anything mapped out and that he's just throwing shyt at the wall? I don't think that's the case at all. 'Peacemaker' Season 2 could very well have been the next chapter to his larger overarching story arc.
Maybe try dealing with the words I actually type instead of making up shyt? Where did I say he just throwing shyt at the wall?
Saying Salvation shyt felt tacked on =/= Gunn throwing shyt at the wall. Two totally different statements. He can have this big plan mapped out for the DCU and still fumble the peacemaker season, which he did.
As far as how do we know, it's evident with how this season turned out. Checkmate, Salvation, Flagg's turn, all that shyt was rushed. Hell they didnt even explain what checkmate was.
Gunn said the original script for Peacemaker ended with the Checkmate montage. Peter suggested doing the cliffhanger/chris kidnap shyt.
Keith was originally pose to be killed.
Felt like he had the character shyt with Peacemaker Season 2 down with the main crew. Chris' arc/Harcourt stuff/Auggie X etc. Those parts were good and fleshed out. But then he got the idea to do Salvation Run and that being part of MoT. Enter episode 8/Finale and using all that to speedrun setting all that shyt up. If all this was the plan when he first wrote the season, then all this shyt wouldve been fleshed out more and breadcrumbs wouldve been dropped throughtout the season.
When you use a show to properly plan out shyt to lead somewhere, you do it with care and get The Penguin. When you rushing to slap shyt together you get Peacemaker S2. Now he doesnt have to waste time in MoT in setting up the Salvation shyt and can jump right into kidnapping metahumans and putting in Salvation. This probably saved them 20-30min in the movie to use for something else.