I received duplicates as well. I know the event is free. But still doesn't feel like it was worth my time investment. Very disappointed and probably won't be playing these types of events again.

This has happened to me about a dozen times over this past week

Hello
Midweek Magic: Standard Shakeup gave me as rewards two rares I already have :/

For this midweek magic my rare rewards were Devastating Mastery and Legion Angel, both of which I already have 4 copies and should have gotten 20 gems for instead.

Same thing is occurring with current blast from the past event

With Historic Pauper this week I received a Flumph for my first ICR which I already have 4x of.

Happened to me too, I am Kaldheim Rare complete and received a Kaldheim rare, and the second one was Swarming Skeletons, I already had 4 off.

I received a Crawling Barrens which I had 4 of, and Volo which I did not have.

Same thing happened for me. Received Elvish Warmaster and Orah. Both of which I already have 4x of.