Microsoft extensively uses A/B testing for potential new features in the Insider builds. Some Insiders get the new features, others don't. Depending on user response and reactions the new feature may eventually get rolled out to all, or it may get dropped. Sometimes A/B testing seems to get used for features in the Retail build. Copilot seems to be one of those cases.
I have three fully supported devices on Retail build, all up to date, all with local accounts. Of those two have Copilot with their local account and one doesn't. Switching from a local account to a Microsoft account should enable Copilot. Sometimes (but not always) it will remain enabled when you switch back to a local account.
In this blog post we’ll talk about the high-level requirements needed for cross-product A/B testing, investigate an online and offline option, talk about privacy concerns, and discuss other considerations
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