May be because majority of his points came in a handful of games. He topped 100 yards 5 times, scored 11 touchdowns (6 in 2 games) but he did have 49 catches
Yes, his huge outlier game could be cause for concern. 251 yards/4 TDs.
But he will only be in his 2nd year, has no competition on a run oriented team, could get his guards back (Nicks toe) and in all reality, he didn't hit stride his rookie year until 6 games in. 1st 5 games, 1 rushing TD, 0 100 yard games.
Next 11 games (incl outlier), 10 rushing TDs, 5 100+ yard games. Plus, as you said, 49 recs on the year.