I'll preface by saying that using the heart emoticons in chat is completely normal at my remote work. It usually indicates "You rock, I appreciate you". Color of the heart does not matter and gender/orientation of the sender or receiver also do not matter at my work.
I'm not wondering about my specific workplace, but I am wondering about external communications. For example, I've with the Teams heart emoticon to a couple external contacts when they send a very effusive thank you email (along the lines of "you're the best!") Is it possible I'm making people uncomfortable and should stop doing that