It's a social issue, not a technological one. People just need to be ok communicating with people who have different styles. Most people do not care to optimize their communication like this and will have a more natural way of speaking, including starting a conversation with "hi".
None of that is how communication works. It requires (basically equal) effort on the part of the sender and the receiver. Gatekeeping communication styles is just a symptom of not having control in other areas.
If people are annoyed by someone saying "hi" then yes, I think they are in the wrong and creating a hostile work environment. I've worked on a lot of different teams, and people who complain about stuff like this are always the single biggest drag on morale. Teams should practice tolerance, trust and flexibility, especially remote teams.
