As of 2020, this is a last release of 2.x version that supports PHP 5.x and PHP 7 versions prior to <7.4.
Only security or major issues might be presented in separate 2.1.x branch (releases tagged as 2.1.x) but any future version is going to be using features of PHP 7.4 and tagged as 3.x.
This release presents a minor BC break. This version might break your coding standard checks (e.g. using AbstractEnum::is() with integer value) but won't affect production usage.