Double check the tense of "is new to" and "was new to" when talking about new features being added. This blurb uses "is new to version 2.3". Given documentation and codebases increase in versions as time goes on, it's probably best to keep this in past tense. Something like:

The ability to set ``validation_groups`` to false was new to version 2.3, although setting it to an empty array achieved the same result in previous versions.