are they dealing with more or less memory safety bugs?

for me it was already "don't run in prod" quality before. (at least after this I'm considering adding it to the CI to see how it fares.)

segfaults. I don't know. I looked at their CI and GH issues over the past few weeks. (though now GH is down so I can't do a search, but I didn't see thousands of segfaults.)

by all accounts and measures it seems it made their house of cards more manageable. despite the frankenport, no?

they already had a zig compiler fork, wanted to upstream it, but the zig maintainer(s) said it's low-effort. now they don't have to maintain their compiler fork. (or wait for the zig team to deliver the features they wish for.) no need to maintain a hybrid codebase. (though it has C++ because of the embedded JSC.)

also I have no idea what's the zig-rust FFI status, but getting over with a rewrite faster is usually better, even if you are left with non-idiomatic code.