Just adding to Charles' inputs - No, Word doesn't make available the information of whether a Heading is used as an anchor for a Cross Reference but there are clues that could be used to determine if this is the case.

1. If the heading range includes NO bookmarks (or only a _TOC bookmark) then it you can say it has not been used in a cross reference. If it does have a bookmark of any type then it MAY have a cross reference.
2. It would be possible to create a macro to show what bookmarks are included in the range and then the macro could toggle all field codes and do a search for each bookmark name. If the search reveals a hit in a Ref field then you 'know' there is a bookmark to that range.

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Andrew Lockton
Chrysalis Design, Melbourne Australia

Thank you for your attention!

I have found this tool extremely valuable:

Cross-references in Word – DocTools CrossReferenceManager

I have a further question I posted in the VBA section