Looks like a moderator moved it to this forum which I think is incorrect. So feel free to move this back to the Everything else WordPress forum ??

1. The strings in translate.wp.org GlotPress are imported from the parsed code of each plugin. GlotPress won’t check wether there is a textdomain or not. If there is a Gettext function, the string is added/updated on the translation table.

About the side note 1, yes there are many plugins/themes where it happens, intentionally or not, wich leads to the next anwser.

2. I guess it’s not up to GlotPress to check if a specific string has the correct textdomain. The same happens when you import originals from a .pot file, textdomain isn’t even used. Some authors may forget adding textdomain, but surely some intentionally omit it so the plugin uses the translation from core, which is wrong, as it is explained in the quote from the developer handbook. Also this generates confusion, because translators do have to translate it so the plugin gets to the minimum threshold to generate language packs, and those translations with no textdomain will never be used.

Appreciate your response ??