That list of core type system soundness issues is long enough that it'd probably be easier to prove Rust style checks are unsound due to incompleteness / halting problem issues rather than fixing all those issues.
The core of the Rust safety model has been proven sound: https://plv.mpi-sws.org/rustbelt/ If you peruse the list, all the issues are either a) places where the actual implementation falls short of the theoretical model, bit there's a plan to fix it, or b) edge-case interactions with peripheral language features (statics and dynamic dispatch).
The issue in question, https://github.com/rust-lang/rust/issues/49206, is such an edge case that there are 0 known examples of it causing a problem in practice, despite the issue being around for many years.
The number of GitHub issues does not correlate to the actual number or severity of issues. After all, rust-lang/rust has more than 120K issues and 9K open issues, but it doesn't mean that Rust has too many issues to solve---those GH issues are mostly means to manage tasks or user tickets to track.