Im sure he will score 50 goals. He had again a slow start, otherwise he would have 40 goals already..
You can't really look at a players season like that. It's a very misguided way to view things. All NHL players seasons essentially have ebbs and flows where they have cold streaks and hot streaks. With elite goal scorers having maybe one very pronounced period. Aho's just happened to be very noticeable because it was in the first 12 games of the season only having 3 goals at that point. In comparison, Auston Matthews had a period in November and December, where he had 3 goals in 13 games. Pastrnak has a period in December where he had 3 goals in 12 games. Ovechkin had a 3 goals in 11 games stretch. The thing is, because Aho's struggle's happened early in the year, it was much more commented on and noticed to the casual fan.
The only situations where it really applies, is if a guy started off lower in the line-up, didn't get 1st PP time and then saw a dramatic change in usage that helped fuel the breakout, and you expect the change in usage to hold.