I really don't think that the NFL should be having its own investigators interrogate victims while there's a police investigation and a range of lawsuits happening. Seems to me like there are all sorts of things that could get very unpleasant and possibly prejudicial.
Read an interesting article about this
Essentially the nfl isn't capable of doing anything right now because they could freak up any legal proceedings, so they won't even investigate Watson.
The unique factor about Watson (vs say Antonio Brown a few years ago) is Watson has not been indicted by a grand jury, but there's a criminal investigation ongoing so he could be. And because of that the expectation is that the NFL won't (and hasn't) suspend him at this time.
So it's completely possible that Watson plays out the entirety of this season not missing a single game. However if Watson is indicted, he could immediately be placed on the commissioners exempt list and be shut down for the year.
So theoretically the Texans could go out clinch the playoffs and then lose Watson to suspension at anytime (presumably for the rest of the season and then some) depending on legal proceedings.
He could also end up playing out the entire season as well. The Texans appear to be one of the worst teams in the league so its likely this is all doesnt, but this could have huge playoff consequences if say there's no movement on any of this until the middle of the playoffs (and the Texans are somehow in them)
(of course I completely forgot the Texans got Tyrod Taylor and that he's going to be their starter, but I imagine there's close to a 0% chance he doesn't get injured like he always does)