As part of the effort to remove old translation drafts (T183890), we want to send users different notifications.
Content Translation allows users to translate from any language into any language and users need an account to use the tool, but that account may not exist in all wikis. There is no guarantee that an account attached to the global user account exists on the wiki where we run the script, unless that is loginwiki where I suppose everyone has one, but CX is not installed there.
As described in T199960#4541334 one option is to run the scripts on each Wikipedia and filter per target or source language. We can also ask Growth-Team for advice.