Sinister Rectus from the Discord found out that some of the text in the first message might be related to Hamilton, the Broadway show. “Your Obedient Servant” is one of that album’s tracks, and that can be found at the end of the first post, along with “IHTB”. Previously, the message contained “IHTHTB” instead of “IHTB”, and that seems to be an abbreviation of “I Have The Honor To Be”, exactly as seen in the song:
“I have the honor to be Your Obedient Servant
A dot Burr”
So now we know what IHTB means - I think it could be "I'm Honored To Be", as "I Have The Honor To Be" in a shorter form.