You might have seen random notifications to chat with Copilot, and/or a yellow highlighted message in settings to backup your copy of Windows [settings only, but they leave that out]. Then there's the ads when you use Chrome rather than Edge. Now Microsoft is showing full screen ads in Windows 10 to make sure you know that support is ending next year, & they're testing ads in Win11's Start Menu. They're also testing an ad for Copilot in Edge's settings.
neowin[.]net/news/so-it-begins-microsoft-starts-showing-full-screen-ads-about-the-end-of-windows-10-support/
neowin[.]net/news/microsoft-starts-stuffing-ads-in-the-windows-11-start-menu/
neowin[.]net/news/microsoft-is-testing-more-copilot-ads-in-edge/