The files that are recreated are enATboldquot* and enATquot* As the bug persists (and only exists when these "languages" are in LINGUAS and --no-wrap is used, removing one of them and the problem is gone, too) I've applied the following workaround: change Makevars and set DIST_DEPENDS_ON_UPDATE_PO to "no" - obvious side effect: the files need to be updated manually before running make dist (I don't know of a way to add a "run only on make dist but not during make distcheck" rule).
Simon