Arsenal has been active in this summer transfer window, and Arsenal signed so many players, and at some point Arsenal was quiet in the transfer window, which I believe was because Arsenal didn't want to bring in new players again this summer, but seeing Arsenal signing Eberechi Eze from Crystal Palace, it is obvious that Kai Havertz's injury made Arsenal go back to the transfer window. Since no one can see the future, we can't really answer your question; we have to wait and see Eberechi Eze play for Arsenal before we can figure out if he can help Arsenal become more deadly or not this season.
I agree with Arsenal swift response, as it's still early in the season giving Eze plenty of time to learn Arsenal game. Havertz hasn't been up to Arsenal standards from the start and with his injury, Eze has an easy chance of securing a starter. He just needs to give his all for Arsenal, and Havertz will lose his place in the starter.