I think when the talking heads look back from 2024, they will put this down as one of the cornerstones of Starmers bid for the 2024 election.
In order to win in 2024, he needs to have a solidly united party behind him with no dissent and everyone "on message". The fact that there is not a lot of noise in the party, I believe, means that the message is getting out about what they need to do for the next 2 years.
In the end it has nothing to do with what the politicians think or want to do, it has to come down to how the Labour party is perceived by the electorate. They need to be seen as a party united and ready to govern.