Why did Alison Krauss cancel Arcadia Tour?

Alison Krauss & Union Station cancelled the remaining Arcadia Tour dates after doctors advised Krauss to take a period of vocal rest [1, 2, 3]. The band said on social media on 10 September that the decision, affecting more than a dozen shows, wasn't made lightly given their commitment to fans, but that protecting her voice came first [1, 3]. The tour had been supporting the group's first album together in 14 years [2].