No, I did not compare him to Coutinho. The closest current LFC players to him stylistically would be Shaqiri, Lallana and Ox. Of course Wilson is not a forward who plays on the defender's shoulder, like Mane – he has different set of strengths such an incredible shot from distance, crossing, as well as a very decent short passing game. If we switch to 4-2-3-1 permanently (as we are trending towards), there will be more room and more need for AMs and less for the forwards.
In fact, you can make an argument that Mane, for all of his great qualities, is less comfortable in this new "control" style – he is too unpredictable for the patient build-up game and often makes a wrong choice, however he's as lethal as ever when isolated 1 on 1 against a defender. It could be good to have a different option, especially on the LW where we don't have anyone other than Mane or Keita, who doesn't really fit there. Notice also that Klopp has recently been trying to find as much time as possible for Mane to play on the right – so there is even more room for a player who is comfortable on the LW to get minutes in that position.