He needs to explain why he tried to get tons of people to work on Canonical adjacent tech, but is now leaving.
He'd be burning bridges with all his contacts if he didn't off them an explanation as to why Canonical tech is no longer something they should contribute to.
I don't agree. He could simply say "After reflection and thinking about what I want to do next in my career, I've realized it's time to part ways with Canonical.". Frankly, that'd be about as detailed as what he posted, but without the parting shot (it's not like he elaborated on his management complaints).
He owes no one a detailed explanation for his decision and it's perfectly normal to keep things like this close to the vest.
He needs to explain why he tried to get tons of people to work on Canonical adjacent tech, but is now leaving.
He'd be burning bridges with all his contacts if he didn't off them an explanation as to why Canonical tech is no longer something they should contribute to.