This Coq proof is an enormous step forward. It's that machine-checked proof I was hoping someone would do when I wrote the above paragraph. 1) Assuming the TCB is correct, we know the Verdi implementation satisfies linearizability. 2) Assuming the TCB is correct and the Verdi implementation and the Raft paper/dissertation/spec are equivalent, then the Raft algorithm satisfies linearizability too.
I'm more willing to believe that the Verdi implementation implements Raft faithfully than I am willing to believe that my hand proof is correct. If you're really worried about (2), you have the option of using the Verdi generated implementation. If you're less worried about (2), you can now have more confidence in the safety of the Raft algorithm in general.