Musk has detailed the plan he envisions for the pioneers/settlers, and it's essentially indentured. Whether it happens or not, Musk certainly has a pretty questionable plan for it.
Ah yes, the “detailed plan” is an off-the-cuff one-sentence reply to a random person on Twitter.
I guess there's a better word for it than "detailed". As a non-native speaker I was under the impression there's a difference between "detailed a plan" and "details of a plan". In this case I simply used it to explain that he had specified his intentions on that front.
Seems like he was just throwing out an idea for how people could fund trips. I think it’s a pretty big stretch to say his plan is to put people into servitude on Mars.