Not quite.
But if he got to "know" the magenkyou since Itachi defeated him prior to Tsunade's-arc... why did it not activate after that?
Why another 3 years later?

What training did Kakashi did during those 3 years? Reading Icha Icha Paradise and Brooding like mad?

While I agree he feels guilty of Obito's death (where is Rin???)... I really disagree that an event of over 16 years (at least) in the past helps him get the Magenkyou...

If traumatic experiences like that worked... then Sasuke would get his Magenkyou just feeling guilty of not being able to save his family from Itachi... no?