Feature request from lisovski, posted on GitHub Jan 22, 2016
Right now there is no way (I'm not sure) to remove columns from CSV/XML export using UI component. It would be good to have "is_system" config attribute in UI component (see Magento 1) to define the columns you don't want to export.
Comment from NadiyaS, posted on GitHub Feb 02, 2016
you are right, now you can not change columns for export. And in the near future it is not planned to be changed.
Comment from tkacheva, posted on GitHub Jun 21, 2016
@asemenenko, @antboiko what do you think?
Comment from tkacheva, posted on GitHub Aug 19, 2016
internal issue MAGETWO-57230