You don't score 20 goals in 16 CL games just by pure luck.
Too lazy to check but I don't think even Messi or Ronaldo had the same stretch during any time in their careers. Certainly not at the start of their careers.
That said, it will surely be interesting to see how he'll overcome this bad spell. It probably never happened to him in his career (even in youth football) to be without a goal for so long. And as a natural born striker he lives for and with goals. Even the greatest players were in poor form at some time in their careers but it's easier for defenders or midfielders to overcome that imo. Striker's confidence and form depends on the goals he scores. He could play well overall, assist a lot but still goals is what keeps him up.
He'll either show mental toughness, come out stronger from this experience and start to bang goals for fun again or he'll crumble under the pressure, "never" score again and his career will only go downwards from here on. He's shown enough so far for me to still confidently bet on the first option at this point.