I did a lot of investigating of the MP / Shenghe relationship, when I was doing some researching about Shenghe for another partnership of theirs.
MP and Shenghe are in a co-dependent love-hate marriage until around 2025, when the divorce is expected to kick in and MP are looking to go off and be alone.
For the time being, they are highly dependent on each other, with each company basically needing the other for different reasons.
MP have nowhere else to send their stuff right now and would face an existential financial crisis if the relationship with Shenghe for some reason ended. Maybe or maybe not there is some change or no change when MP are looking to start with their NdPr in 2023 but that's still only one piece of the puzzle and is likely to not much affect the overall picture.
MP clearly aren't keen to talk about it, but unless there is an explicit statement of change otherwise, it's MP and Shenghe as partners until 2025.
You can bet your little hearts that MP are doing everything they can to get their whole thing up and going by 2025, but it's simply going to take time, they just aren't ready soon.
If you are keen to do your own reading on this, the best place is in MP's stuff, but really their SEC Filings, which are lengthy but also pretty blunt.
https://investors.mpmaterials.com/overview/default.aspx*
In regards to Lynas, I don't think we can draw many conclusions at all right now. I think it's just waiting to see how things unfold over the next couple of years. We're more likely to hear something about partners closer to home before then.
(20min delay)