It's easy to claim all this after the outcome,

I mean sure that's true but that statement cuts both ways. You can claim Corbyn did well because everyone underestimated him but then the counter point is no-one expected May to be such a terrible campaigner and for the Tory manifesto to be such a mess. Maybe if Labour had it fully together there wouldn't have been an election at all at this time and who knows what the political landscape would have been like in 2020.

As for pre-election predictions yes a lot of people were originally talking about a Tory landslide but May was rightly getting a lot of criticism towards the end of the campaign and the polls were putting Labour within a few % points of the Tories so they turned out to be reasonably accurate.

Having a more representative PLP is the best way to maintain unity and avoid petty conflicts in future.

I mean again that's correct if you assume all of Labour's vote share is on the back of Corbyn's policies and disregard the other factors at play in this election. The majority of those in the center/center-left will have voted Labour regardless of whether they are entirely on board with Corbyn's ideology to oppose right wing Tory austerity... are you sure it's a good plan to jettison them if you want to win rather than forming an alliance? We can probably assume that's at least 20%+ of current members (based on O.Smiths 40% vote) and a large amount of the experienced Labour MPs fall into that faction as well as a sizeable amount of the electorate. Atm as far as I can see Corbyn seems to have gained some acceptance from these people which is exactly what he needs to actually have a chance at winning the next election. Labour still has a mountain to climb to win that and continueing the divisive politics within the party when it seems there is now an opportunity to form a consensus is a bad plan (which is probably why the "Torygraph" is running this story).