You're getting evidence directly from someone who is a senior member of the Rust community and who participated directly in the original decision.

Imagine you hear a series of bangs, walk into your living room, and see Alice holding a smoking gun and standing over Bob's bullet-ridden dead body, holding a note saying "I wish Bob was dead".

One response is "well, we don't know what Bob did or if Alice actually pulled the trigger". Another response is "um, Alice, can you explain why you seem to have shot Bob?", and if Alice doesn't want to explain anything, you might start to draw inferences. But either way you might not want to hang around Alice until it gets cleared up.

Being invited as a keynote speaker lends you credibility and status. It means you have been acknowledged as someone worthy of giving a keynote. You may not care about this, but other people do.

To downgrade someone from a keynote speaker to regular speaker is extremely disrespectful. Especially someone that you invited.

It makes it seem like you are toying with this person, and based on JT's account someone on the Rust team was toying with JeanHeyd because they went behind the rest of the team's back to downgrade his talk.

It's like giving a child a toy then snatching it back. It's just cruel. Whether it was a mistake or not doesn't change that.

One wrinkle I haven't seen called out is whether this was a paid speaking event (I assume it was) and if the demotion came with a part cut. If there was a pay cut that pretty shitty IMO, and does get a bit closer to losing ones job.

Of course you can just not care and let people walk all over you every single time, but that’s not a healthy strategy either.

It's a respect thing. It costs time and money to produce and give a talk.

That very often isn't visible to the audience. It takes weeks of dedicated preparation to deliver a high-quality keynote talk, and people have day jobs and other obligations. If they're going to travel hundreds or thousands of miles and now have to pay for the privilege, they might want to not be treated as disposable.

That doesn't seem like too much to ask.

It’s like being center stage on the PR poster for the movie and then only being an extra.

Like, being invited to perform on the main stage of the concert with your band, and then later being told you’ll have to perform from side stage 3 instead.

The audience is confused, and the whole thing is just disrespectful, yeah.

The thing itself is not the problem, performing on stage 3 by itself would be fine. It’s the disrespect and incompetence implied by the switch from one to the other.

Status, credibility and respect are real and tend to matter a lot.

It's not "an ego thing".