Short answer: No—SharePoint doesn’t have a built-in setting to make “Check in comments” required, and there’s nothing publicly available that indicates it’s on the roadmap. Practical workaround: add a required text column such as Change Notes on the library, and use Power Automate on When a file is created or modified (properties only) to (1) detect a check-in (Version/Checkout status changed), (2) if Change Notes is empty, undo the check-in (Send HTTP Request to SharePoint → UndoCheckOut) and notify the user (email/Teams/Adaptive Card) to provide notes, and (3) optionally copy Change Notes into the version comment for traceability. This enforces comments without relying on the native check-in comment box.
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