As long as it's not proprietary, I don't think there are any consequences other than ideological. Open source projects require some kind of legal entity to represent them. Rust is going for an independent foundation created specifically for this purpose. TypeScript has that legaly entity in the form of a company that owns the copyright and trademark.
This is not something that end-users should care about, however. There have been many examples in the past where an open-source project was mishandled by the owning company and a community fork appeared as a result. That was also the case in JS world when Node was (briefly) forked after Joyent (Node owner at the time) was having trouble governing the project.
As long as it's not proprietary, I don't think there are any consequences other than ideological. Open source projects require some kind of legal entity to represent them. Rust is going for an independent foundation created specifically for this purpose. TypeScript has that legaly entity in the form of a company that owns the copyright and trademark.
This is not something that end-users should care about, however. There have been many examples in the past where an open-source project was mishandled by the owning company and a community fork appeared as a result. That was also the case in JS world when Node was (briefly) forked after Joyent (Node owner at the time) was having trouble governing the project.