first of all: It’s SO good to read an updated version of this book! Thanks for all the effort!
The text says:
Both strings and regular expressions have a match? method which is synonymous to the =~
While the two are very similar, there ist a difference in the return values (at least): ‚=~’ returns an integer or nil, ‘match?’ returns true or false.
See Class: Regexp (Ruby 3.1.2)