Expression of regret. "I am truly sorry." - Check.
Explanation of what went wrong. "I must have directed angry words at you, who clearly had nothing to do with how the day had gone." - This is weaselly. "I must have...", not "I did".
Acknowledgment of responsibility. " I clearly forget that I am the oldest and most experienced—and I should act this way in a post-mortem conversation." - Weaselly. Whether he was oldest and most experienced or not, no one should behave this way. And rather than taking the responsibility, it's chalked up to forgetfulness.
Declaration of repentance. - Nothing here. No commitment to change. No stated intention for better emotional management.
Offer of repair. - "Finally, as you surely recall, I encouraged you throughout 2019, in person and in email, to join the Racket leadership;" In the absence of any kind of effort or commitment to change, this would not be received as a positive offer. But rather an extension of exposure to an abusive individual. Not much of a repair.
Request for forgiveness. - Nothing here either.