Renaming them seems logical, but since they pass through low density areas in Sweden it probably won't ever happen.
Their E4 and E6 are the only exceptions to the naming convention, that north/south are odd numbers and west/east are even numbers. E4 and E6 should have been renamed in the early 1990s to E47 and E55, but they got to keep the old names in Sweden, because nobody wanted to pay for changing thousands of existing road signs.
So does the Pan American Highway, but if we are willing to call that 30,000 km, i am willing to give the Euros their 5,000 km highway to feel important.