Being in pediatrics, and consistently being fascinated by psychological research related to language, I have been thinking a bit about this over time. While it is not a direct answer to your musings, I have posted a link to an interesting JAMA article studying use of emojis amongst communication amongst medical clinicians:
of note, The authors statement on the emotional piece is quite interesting.
"While clinicians rarely used ideograms to refer to objects, events, or ideas (11 [7% of tokens]), these symbols nonetheless added at least some new information in the majority of instances (122 [71%]). Clinicians used ideograms most often to add emotive content to their texts (61%). In particular, they modulated the intensity of speech acts as in the message “just add flagyl for anaerobes and ditch the clinda!
🙂.” Because emotions are often conveyed through features of language not representable in standard orthographic format, the addition of this information through ideograms can provide important contextualization, evaluation, and disambiguation for the messages to which they are added."
In contrast, the following article,
https://journals.sagepub.com/doi/full/10.1177/1932296820965588
describes the endorsement from pediatric patients with type 1 diabetes suggested "some adolescents reflected on how support in the form of comments and likes felt superficial. Given that many members of their social media communities do not understand the burden of diabetes management, even positive responses could create feelings of alienation."
Either way, it's an interesting development over the past decade or so.