I have a great recommendation for the Microsoft team.
These types of mistakes in the product management level happen frequently at Microsoft.
This feature was the only one useful feature on the outlook mobile app and is being removed without an alternative. The alternative is Copilot? and when I search what it can do , reading your emails out loud is not one of them.
I have a solution for you. Fire those that made this decision, and that will ensure this type of blunder will never happen again.
If the product manager doesn't use this feature on a daily basis, it should not be a product manage to make the decision.
Microsoft is the master of taking useful features away.