What problem does this feature solve?

When I hover over the select option in TimePicker its value is displayed as the input value, but when I close the picker without selecting it reverts to previous value.
It is very confusing for users, and I would like to be able to disable the preview value in the input. The value is already shown as a hover in the select list - no need to show how it would look like in the input, in my opinion.

What does the proposed API look like?

showPreviewValue?: boolean = true