bug(mat-option): aria-selected is always false when used inside multiselect mat-autocomplete

[tHe-AK]

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

No response

Description

I tried creating mat-autocomplete with multiselect options along with a checkbox following a StackOverflow answer:
https://stackoverflow.com/a/50569422/8043493
The functionality works fine, but the aria-selected attribute for the selected option is false. I tried setting it explicitly using attr.aria-selected, but it is not working.

Reproduction

StackBlitz link: https://stackblitz.com/edit/w8j5bi2o
Steps to reproduce:

1. Select an option from the autocomplete.
2. Navigate to the same option with a screen reader opened, OR check the aria-selected attribute value for the selected mat-option.

Expected Behavior

The selected mat-option should have aria-selected as true.

Actual Behavior

The selected mat-option has aria-selected as false.

Environment

• Angular: 15.0.5
• CDK/Material: 15.2.9
• Browser(s): Edge
• Operating System (e.g. Windows, macOS, Ubuntu): Windows

[crisbeto]

Closing since this isn't a configuration we officially support.