Microsoft seems to be rolling out a new Microsoft Advertising console design. The new interface is more modern and possibly more efficient to use.
Hana Kobzová notified me of this change on X saying, "New online interface is being rolled out. It is modern, sleek & fast and very similar to Google Ads."
She posted screenshots on the PPC News Feed blog, here are some of those screenshots - you can find more on that site.
The last time Microsoft released an interface update for Microsoft Advertising was in 2020.
They also updated the sidebar navigation:
You can learn more over here.
Forum discussion at X.