Agreed on Smith and Agholor, though I'd withhold judgment until their 2nd year in the system and with a QB that's no longer a rookie (not that Mac will be a finished product next season but he should be noticeably better).
Disagree on Henry and Bourne. Henry had 9 scores. And they got 800 yards out of Bourne as a 3rd option, which is worth a lot more than the 3M he got paid.
The big caveat, and I know it sounds like excuse-making but it's a real thing: all of those guys were in the first year in a new offense with new QB who happened to be a rookie. If they all have the exact same production next season, then I'd be disappointed. Until then, we have good reason to be excited about 2 of them (Henry, Bourne). We'll see about the other 2, but at least Agholor is in the last year of his deal.