Understood, Webb can declare anything they want but note that their claim regarding the numbering system is also questionable. There is legal precedence that has been set that says numbering systems is NOT copyrightable, there is not enough 'creativity' in a compilation of numbers. Think about it, if folks can copyright a numbering system than virtually every numbering system that could be created would already fall under someone's copyright claim. "My copyright covers the numbering system that assigns #1 to the first and and increments by one after that" Obviously not.
Before 1991, copyrights protections were granted based upon an author's work effort/diligence invested during the creation of the content including things like databases, directory, or catalogs; significant creativity or originality was not required. But the Supreme Court decision in Feist Publications, Inc., v. Rural Telephone Service Co., 499 U.S. 340 (1991) https://en.wikipedia.org/wiki/Feist..._Service_Co.
changed this in the ruling written by Justice Sandra Day O'Connor.
But regardless, the copyright laws contain 'fair use' exceptions; that is a fact. The only question is if this falls under 'fair use' or not; in my lay person opinion it does. If a lawyer has an opinion or if anyone can cite an actual legal reference I'll reconsider.
Edit; In my opinion any author or publisher with vision beyond the end of their own nose ought to welcome mentions and snippets as a form of free advertising for their full work.