This is a question of, what agency do you have over your communications and what kind of communication would express a character trait of yours that you would like to be attributed to you.

If you have high agency, and using emojis expresses genuineness or what you would prefer to be expressed, go for it.

I swear in meetings, drink at lunches, and generally wear my feelings on my sleeve. This works for me because I have useful feedback on projects, clearly define choices effected by policy and what have you. I say those unsaid things, and either it’s novel contribution or it’s falling on the sword of the things people don’t want to say. This is fine for consultation. It does piss off colleagues when I just do what I want, to effect some result or uncover some relevant fact that I assume is required.

If you have low agency, and/or you feel that informal communications would be detrimental, find a communication strategy that lets you express some individuality, novelty in some other way.