If I correctly understood the code here, it seems that this issue is related to this code https://github.com/xwiki/xwiki-platform/blob/xwiki-platform-14.10.10/xwiki-platform-core/xwiki-platform-web/xwiki-platform-web-templates/src/main/resources/templates/edit_macros.vm#L26 which has been added for fixing XWIKI-15228 in commit https://github.com/xwiki/xwiki-platform/commit/b2b6a1569bb1aca55565a322bf355a01111ccb27 . However, there is no indication in XWIKI-15228 that this side-effect was intentional, so it would be a regression...