I strongly support the “no hello” concept but I also fear being seen as “that guy” so I never mention it. Sigh
Usually within a few minutes there's followup context sent. Either the other party was already in the process of writing the followup, or they realized there was nothing actionable to respond to and they elaborate.
A: Hello!
B's bot: Hello to you too! I am a chatty bot which loves responding to greetings. Is there a message I can forward to B?
The concept simply needs a more descriptive name to be accepted. It's not about not saying hello. It's about including the actual request in the first message, usually after the hello.
You just can't win.