The leak seems to be legit and not a prediction. The classic black and white stripes will feature in the home shirt while they’ll be thinner than those in the current season. Castore will add a cyan logo to the left with the badge represented on the right. The collar and cuffs will be white with a thin black line through the center.
The third jersey comes in a dark blue tone and features golden logos and accents, including a monochrome club badge. Completing the look is a bit of trim at the front of the collar as well as a fading graphic on the sleeves just over the cuffs—the most creative feature on both kits.
UPDATE: Although not a Newcastle leak per se, FootyHeadlines.com also obtained a picture of the Wolves goalkeeper shirt for next season, which is also manufactured by Castore. This is how that kit would supposedly—again, 99% possibility that’s the final design—in Wolves’ threads.
Newcastle’s goalies have worn a purple kit this season so that Wolves leaked shirt might actually be the same as the one sported by the Magpies goalkeepers next season. Newcastle also has a yellow/orang-ish kit for GKs this campaign, which might look like the one below (my prediction; this is not a leak.)
No information about the actual launch of the kits has popped up yet, though they should be coming around late June or early July.