The bug is partially tracked under the community-managed Doomfist Buglist, in the “Rocket Punch Issues” section, under the name “Rocket Punch Charge-up Animation Faults”.
Full credit to daavel_ from the GetQuakedOn discord server. I did none of the work, but I am willing to take all the credit.
Since the release of Overwatch 2, Doomfist had a lot of animation issues. A community member has compiled them into a video: https://www.youtube.com/watch?v=dqilQxpZhco
Other reported Doomfist bugs, unfixed at the time of writing this report:
Doomfist does not block bounced projectiles properly
Doomfist Rocket Punch knockback stops on invisible walls
Doomfist Meteor Strike camera bug (cont.)
Doomfist Rocket Punch acceleration gets staggered by melee
Doomfist's Punch cooldown does not reset on being empowered
Doomfist's Punch gets stuck on a deploying Anchor Drone
Doomfist's own slam overrides Rocket Punch knockback
Doomfist cannot knockback Anran coming out of Dancing Blaze
Doomfist gets stunned by Domina when he shouldn't
Doomfist cannot fully block Vendetta's Projected Edge
Doomfist’s Punch momentum can be overridden (cont.)
Doomfist’s Punch stun allows for some ability usage (cont.)
Doomfist's Rocket Punch allows targets to move before stun
Doomfist's Rocket Punch removes stun from enemies
Doomfist block logic is extremely inconsisntent (cont.)
Doomfist's Rocket Punch momentum can be overriden on stairs
Doomfist's Magma Titan skin blinds the player when blocking
Doomfist gets knocked down too late when punching Brigs Bash
Doomfist's Punch gets stuck on deployable objects too often
Doomfist is unable to stop Baptiste from using Exo Boots
Doomfist cannot apply full knockback to Vendetta in ult
Doomfist is unable to cancel Vendetta's Soaring Slice
Doomfist's Punch momentum gets overridden by some abilities
Doomfist's Slam is unable to hit targets close to Ice Wall
Doomfist's Slam doesnt work on a rising Ice Wall
Doomfist's Rocket Punch goes through Mei's Ice Block
Doomfist cannot override Freja's Updraft momentum
Doomfist's Rocket Punch stun allows for some ability usage
Doomfist is too slow when going up slopes in Meteor Strike
Doomfist is unable to go over some slopes in Meteor Strike
Doomfist's Punch doesn't work on a rising Petal Platform
Doomfist's Punch doesn't work properly on a rising Ice Wall
Doomfist cannot block Freja bolts under some conditions
Doomfist's Slam doesn't work on a rising Petal Platform
Doomfist Meteor Strike camera bug
Doomfist block logic is extremely inconsisntent
Doomfist can only block Illari ult under certain conditions