That sounds like typical scrum-enthusiast double-speak to me! :D

https://www.scrum.org/resources/what-is-scrum

"This Guide contains the definition of Scrum. This definition consists of Scrum’s roles, events, artifacts, and the rules that bind them together."

Definitions, Rules, Roles, Artifacts etc. Sounds pretty authoritative to me. If it wasn't authoritative, how would you even know what SCRUM "really" is? You cannot say both that SCRUM is not authoritative and lets you do what you want, and then also say "you're not doing scrum correctly".