This is the same bug as
XWIKI-13084 which I could reproduce on 7.4.2 with the same use-case:
- Create two new wiki, called WikiA and WikiB
- On WikiB install an application like Ideas (that has its title translated inside a TranslationDocumentClass object with visibility WIKI)
- Try to copy/rename a page from WikiA to WikiB, see bug.png
- In the 'Select Page' modal the translation for the homepage of Ideas app is not translated/rendered.