Do I owe my employer the courtesy of training the person who got promoted over me?

I made post over in r/AMITa, overwhelmingly it seems everyone thought I wasn’t being horrible by refusing to train my replacement in systems I had worked very hard on and had to figure out myself.

There are three issues here:
1. I was promised this promotion. Yes it is a government job, but because it was an internal posting they had the ability to not open it to everyone and simply promote as promised. I went along with it because I was confident I was qualified, but they said they based it on the interview alone, no previous experience which is sketchy.

1. I’ve worked very closely with these people for years, through the pandemic. I’ve always been honest with them, neither of the two people involved came to me before or after the notice to tell me next steps or offer a review.

2. I had to ask, what are the expectations now that your wiped out 3/4 of my job duties? They played dumb. The stated it was up to me. I said the onus was on them to define my job now. I said I didn’t want to hurt the office, would hand off my duties, but the two big projects I worked on, they would have to figure out. It was simply wrong of them to do that, 2+ years of work on milestone projects taken away. Funnily enough they agreed but didn’t offer to mitigate any of the losses. I also asked for a post Mortem review and they refused because I interviewed well, the outside interviewer they brought in for optics purposes liked someone else more.

I sent them a clear list of duties asking for clarification on what should be handed off and how. The 15 other sundry duties I’ve done out of the kindness of my heart like tech support and liaising with legal, business systems and IT are no longer my responsibility.

I think I’m being reasonable by handing off my duties, sending out introductions to the appropriate offices and wiping my hands clean. Two co-workers came up to me and asked what happened, that XXx isn’t qualified. I really don’t know. The lost infuriating thing is the lack of professionalism on my two supervisors parts. Honesty is the best policy.