It's not absurd in the slightest, saying he's prolific after a good patch would be as absurd as me saying he doesn't score any goals after a poor patch, which may be what follows in the weeks to come. Who knows.
The point is, look at his overall record. This year, last year and the year before. It's good, but not amazing for a top level player, certainly not a £70m player. I repeat, his goals per game ratio matches that of Giroud and if I called him prolific I'd be laughed out of the forum.
Lastly, consistant =/= prolific.