This isn’t tagged with either bug, or accepted, it’s just an issue. There’s substantial debate within that thread about what the problem actually is, I think your confidence is unjustified.
Andrew also tagged it ‘unplanned’ so, there’s that.
Yes I think it would be foolish to tie lifetimes to block scope in addition to function scope. There was a long thread about this awhile back, my position is that better liveness analysis solves the excessive stack use, and with that solved, all that block-scoping lifetimes would accomplish is breaking obviously-useful code like that shown above.