I'm an ajax fan and remember this well (it was a foul against tagliafico I believe and I think mazraoui had gotten a red already).

Anyway, I totally agree with your assessment. You can see Rashford planting his foot to shield the ball. He's not trying to touch the ball, he's stomping his foot on what he hopes will be the ground but ends up being someone's ankle. It's a shame for him but easily avoidable.

These things used to be yellows at most. I personally am happy with VAR and think this should be a red.