The truth is, teams have plenty of levers to pull. There's the aforementioned $70,000 fine for skipping a mandatory minicamp. There's the penalty -- up to $30,000 -- they can assess the player for every missed day of training camp. They can also dock each guy the equivalent of a game check -- 1/17th of his salary -- for missing a preseason contest.
Now the specifics of this have changed due to the cap number going up and the league schedule changing, but the stipulations and clauses still exist. Hopkins will have to forfeit his $445,000 roster bonus if he does not report before Wednesday. If he does not report to camp before then, the Texans would be able to recoup up to 25% of that signing bonus, along with Hopkins forfeiting his weekly game check.
Only Kam Chancellor has taken a holdout into the regular season under this new CBA. Chancellor was able to do so because the season before, he had signed a new deal with the Seahawks, meaning he could theoretically withstand the fines long enough to make the Seahawks cave in. This obviously did not work for a variety of reasons, but the key point here is that most of the holdouts are from players still on rookie deals. This means that there isn't as much room for these players to leverage new deals because the team knows that they could potentially keep fining the player until the players cave.
With the Texans placing Nuk on the "Did Not Report" List, the Texans are turning the screws on Hopkins and his agency, CAA, in order to bring him back to camp. Hopkins' room for negotiation has been severely reduced, and it's looking likely that this holdout won't last much longer. As to whether Hopkins will report back to camp with a new contract, we cannot know. We can only hope that this move hasn't damaged the relationship between Hopkins and the team to the point where future negotiations don't occur.