I'm sure this has been asked before. Can you still do your Epic 2.0 even though you completed these two?
You'll want to do ER no matter what. But yes, you can do BOTH epics, 1.0 and 2.0, after you complete ER.
Epic 2.0 is a completely separate item from ER. Epic 2.0 can only be completed if you have your ACTUAL EPIC 1.0 weapon though. ER doesn't count for that.