You're high if you think DP made or saved acts like The Weeknd or Pharrell. Timely, successful and probably wise collaborations yes, but that's a two-way street in each of those collaborations. Pharrell's never really lost relevance and that's pretty understated; the dude is a legend in his own rite and that is not hyperbole. Arguably the biggest contribution DP made to his career was to push him front and center into the spotlight to be a frontman rather than just a behind the scenes guy, and I'm pretty certain he's said as much about their effect on him.

The Weeknd has been on a meteoritic rise since Trilogy and I'd argue that the singles from BBTM were bigger than the DP collabs, though there's still time for them to gain in popularity I guess.

Moroder specifically did have a little career resurgence along with Nile and Chic, and that I would attribute to their collaborations on RAM, but I don't think it's been all that significant.

As far as Alive 2007 and the impact that production has had on essentially every live electronic music act since, I don't think it's debatable. That production was a landmark.

In any case you're talking about at least a few different things. Yes they've innovated and helped to steer music to a large degree, but I don't think they're as responsible as you're implying in kickstarting or reviving the careers of their collaborators.