About the gun emoji being a toy:
As a philosophical aside, I can also see how any emoji choice is an influence on our expression, meaning it's also denying us some other emoji vocabulary. Let’s not forget that we need words even to express the worst ideas, otherwise we can't talk about them. We could also ask: is it even the Unicode Consortium’s role to attempt to influence the representation of violent or unethical ideas?
Limiting the possibility to express yourself is the way to avoid
About the platform representation of an emoji:
In this 2018 survey on emoji rendering, 710 Twitter users were shown how their tweets look on another platform. 18% of the participants declared that they would have “edited or not sent” a tweet featuring emoji, had they seen how that tweet appeared on other platforms.
More recently, this 2020 study on cross-platform emotional interpretation asked participants to pair emojis from Apple, Google, and Samsung with emotions. Emotion-emoji pairs weren’t always consistent, and emoji interpretations varied depending on the platform, suggesting miscommunication.