It is just indicating there is a E in the word in a different position. That the exact positions was found in a previous attempt does not matter, i think i.e. each guess is independent from previous guesses.
You are confused. Just because you found E in the right position doesn’t mean later guesses will no longer show the existence of an E. The only way to know if there are more than one letter is to guess two Es in the same word. If both are marked, you know there is two letters. Dordle does not “remember” you found an E and stop marking it as existing
There is another situation where you can determine if the word has two of the same letter. If you guess the letter in a different spot and it is correct, it will also turn green. Example..
Let's assume the puzzle answer is CHEEK
First guess is FRESH - "E" in the third position turns green and the "H" turns yellow
The second guess is LOVER - "E" in the fourth position turns green.
You now know the word has two "E's" in the 3rd and 4th positions and an "H" in position 1 or 2.