Warden sonic boom attacks can hit endermen, shulkers or players who have finished eating chorus fruit and players who have used ender pearls within range, even if they have teleported

I can confirm this behavior.

It should only hit you if you are still in range the moment it finishes the attack. Is there a good way to reproduce that is not 'timing sensitive' ?

While still within attack range, the sonic boom should be a straight-line shockwave (judging by particles) and shouldn't still take damage after teleporting.

But damage and particles are done at the same time, so 'at that time' the entity taking damage was there.

@@unknown, particles and damage are indeed more synchronized in 17a.
I will close this issue and create another related issue.

See MC-251239.