Haizz, I've just learned to use Webpack. Now comes SystemJS+JSPM. There are just too many new tools, workflows and different ways of doing things in Javascript world.
You don't have to try to learn everything. I know HR throws the kitchen sink into job listings, but it's okay to specialize in only one copy of a particular tool.
No, because SystemJS+JSPM does nothing to invalidate your Webpack knowledge. It's still an active project that works just fine for the needs of many developers.
This is a trite response. If it does something significantly better than it does do something to invalidate knowledge in a defacto sense, at least for the caring craftsman.
Not that there's any point complaining about it either though...