Microsoft has updated its help page to clarify that View-through conversions are now tracked for Multimedia ads, in addition to Audience campaign ads and Search ads extended to audience targeting.

This extension reflects a shift in Microsoft Advertising, enhancing metrics available to advertisers operating across multimedia platforms, thereby allowing for better performance evaluation and strategy adjustments.
Previously, the tracking feature did not include multimedia ads, limiting it to audience and search campaigns only.
This update was spotted by Hana Kobzová.
Read the official help page here: View-through conversions.