I honestly am not too disappointed. It's important to keep expectations measured. Yes, Nadal automatically becomes one of the favorites whenever he reaches the second week, but even he, prior to the tournament, was keeping his expectations grounded, and not in the typical "downplay your chances" sort of way. He wasn't going to win a slam so soon. Let's not forget this is virtually his first tournament back. Roland Garros 2013 was not his first tournament back after that comeback, and he'd had plenty of time to rediscover his form. I don't expect similar results this time around, but let's wait and see.
Ultimately, I wouldn't call this tournament encouraging nor discouraging for Nadal. It was just about what it was. Like I said, movement is the key. If that's a sign of things to come, it's a problem. If he'll still be able to move better when it matters (as he hasn't moved consistently well in a couple of years), the same way he's been able to do as he's gotten older, it won't be a problem.