The proposal is made for consistency with the naming used for the same setting in the 'Table of Contents, Index or Bibliography dialog'. Also, when 'Protect against manual changes' is on, it does not prevent against removal of the table of contents section. For me, 'Read-only' conveys that removal is not possible. Possibly 'Read-only' was chosen for use in 'Indexes' popup menu in the Navigator because of its length compared to 'Protect against manual changes'. I have already made a patch that makes the proposed change in the case it is decided this is an improvement: https://gerrit.libreoffice.org/c/core/+/194806/1
Makes a lot of sense to align this label with what we have in the ToC edit dialog. String +1. Please keep in mind to add ux-advice@ to CC when adding needsUXEval.
Jim Raykowski committed a patch related to this issue. It has been pushed to "master": https://git.libreoffice.org/core/commit/a4b2d74bc30fea3eba101106f4686d881f8aa9ba tdf#169800 SwNavigator: Indexes context menu item name change It will be available in 26.8.0. The patch should be included in the daily builds available at https://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More information about daily builds can be found at: https://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.