The SSPX priests are supposed to be teaching and explaining why such uncertainty is a false concern and completely unwarranted - and why it goes hand in had with why the SSPX exist in the first place! - as they used to teach and explain since the 1970s no?
WTH are they doing "conveying deep gratitude" to the pope for putting NO enemies in a position of authority to validate anything, especially, of all things, validate the sacrament(s). 
Yes they used to be very strong on this point since it's the whole and only reason for their existence. Not only that but in addressing VII errors and all that that entails they were effectively teaching the Faith to the faithful. How many of us would know about supplied jurisdiction without them? The NO priests sure as heck aren't about to teach it. It's true it didn't convince everybody but it's truth and those who have ears to hear will hear.
But now that in the minds of +Fellay and co. their reason for being has shifted to saving Rome by their traditional prowess, I suppose these details are just not important anymore. Keeping up appearances and worrying about what the mainstream thinks of them (those who know nothing of supplied jurisdiction and don't want to know) becomes what's important. Now the whole world will
know the SSPX is valid. Great! To them it's a win. Never mind that people think it now for the wrong reasons or that the move ensnares the SSPX to the usually-very-unfriendly diocese. The fact they've been valid all this time, the fact that this is a huge teaching opportunity for the faithful and whoever in the world is interested by this, becomes a little detail they can afford to let go. I really hope they come out with more of a statement regarding supplied jurisdiction because the groveling and playing along is really sickening. If they don't, then I hope there are individual priests still left out there who will take advantage of this massive opportunity to teach the truth.