After running it through a minifier you get this:
As you can see privateStatic was not renamed to a shorter name as you might have wanted.
One way we can remedy this is to move the private static variables up into the module. As long as you don't mark them with the export keyword they will be completely hidden from the outside world.
One problem with this technique is readability. Notice that I change the name from privateStatic to _privateStatic. I prefix the variable names with an underscore to make it clear that they are defined outside the class but are still private.
If you have a lot of static variables or constants in a class and you're looking to save some bytes in your minified application you might take a look at using this technique. It may make your code a little harder to read but the trade off is you get a smaller app.