> As one of the comments in the linked issue points out, dropping IE11 means they can also start using basic JS constructs, like Array.prototype.forEach.
And if you can polyfill, that is good way to drop support for ie11. Personally instead of support ie11 out of the box, have have create custom build or expect them to do polyfilling themselves. This way they can optimize for the remaining browsers.
Array.prototype.forEach is supported from IE9.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...
EDIT: It is the nodelist api that isn't supported in IE. Not Array.prototype.forEach.
Quite a lot of these basic JS constructs even if they are missing (most aren't in IE11) are very easily polyfilled.
Personally I think it is fine that they drop support if they don't feel the need to support it. Bootstrap 4 isn't going to vanish.