I don't understand what you're saying. I suggested that linux builds of rust+cargo ought to be done as musl-static (not for targeting musl) so that a single download works on both Ubuntu and Alpine. Now we have only glibc builds. Yes, it's not related to servo, but it is relevant to you mentioning glibc, though this is off-topic so let's stop arguing.
I think you should go back and re-read the conversation, particularly kibwen's comment above and your reply: they seem to be totally unconnected. I was trying to understand how you thought they (Servo upgrading Rust versions and a musl-compiled rustc) were related, I was not arguing. There is in fact no mention of glibc until your comments, nor is there any implication in my comments that I don't understand what musl does nor do I disagree that it is useful (in fact, I used Rust's easy ability to link binaries against musl just a few days ago). This discussion is purely prompted by me trying to understand why you thought it made sense to talk about musl on a seemingly unrelated comment... maybe there was some insightful connection I missed, but it seems not.