It's not that bad of a move for the Texans if its known that Hopkins wants a new deal. He just locked up the third year of a six year deal and all of the guaranteed money was 2017-2019. He is now locked at 12.5m per and change the next three years, wants to surpass Cooper's contract that should be north of 20m per season.
So let's say he wants 22m per season. You can only have 6-7 top contracts in this marketplace when your QB is about to reset the dynamics of the overall team cap covering 20-25% of it.
They get a dual option RB out of the deal and 2nd round pick. They have two more WRs with talent and another one that could not get on the field, but showed flashes when on it. They have a chance to add a cheap WR in the draft and restock around what might be a tight cap shortly.
It's a horrible trade for Houston when you consider what Minnesota got for Stefon Diggs. Buffalo gave up an emir's ransom to get him, and Diggs doesn't have Hopkins' pedigree.