I ask because this link: Sweetheart | My Little Pony Tales Wiki | Fandom basically has it marked up as such and I suspect that is somebody forcing their head canon as actual canon.

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Gonna say No. That doesn't sound right and I've recently watched the entire series on Tubi. That's definitely someone's head cannon on the loose there.

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Thanks. That let's me know that Sweetheart would be the name to use in games.