Probably Apple gave these journalist an Apple Watch for a pre-release review with the sole condition that they must wait until today to release their reviews.
On the contrary, people with a review unit tend to actually use it before the review. People who have to buy it on release date and then get a review out ASAP tend to do much more republishing of market materials.
Journalists getting review units does mean they are on the "take" or shills. If the journalists don't have to send the review units back, then I would filter those. MEven John Gruber has written about how he sends the review units back to Apple.
How do you figure? They were given an Apple Watch - a real, functioning one - to review a few days early. I'm not sure how that means they are "republishing marketing materials".