This is arguable a big idea of free software: trying to jealously hoard the value for ideas that are naturally freely copied and shared is just plain inefficient.
So yes, in this case it would be nice if these interns got a big pay out, but if they did, then the megacorps wouldn't bother using Rust because they plan is already to just outbid all the non-monopolists for workers rather than actually be productive with their workforce. And C++ and whatever else are already free, so Rust has to complete with those.
The only way to make things more fair is just give up on meritocratic value capture, and just do a big tax and big UBI, so just as free software is free to use by all, some of the value created in the use of free software is also freely shared by all.
Just limiting to software engineering (there's other lucrative fields out there) you can easily make a six-figure income remotely. This gives you the freedom to live somewhere with very low cost of living. It's not hard to build wealth this way.
You could debate that getting the necessary skills to get a job like this is harder than it should be.. that corporations themselves are broken.. whatever your worldview is that's fine but "cannot get wealthy off salary" is just plain false.
This is quite contradictory and proves my point.
You can make hundreds of thousands of dollars a year as an engineer, without even talking about stock. I'd call that wealthy. If you're an engineer of some stature, 7 figures TC yearly is not out of reach.
So now companies make billions off of the software written in Rust and has even one student become a millionaire? Companies that appropriate such projects should start paying their fair share to people who made it possible for them to make such profits.