I assume no US outlet wanted to pony up the money yet. And the whole story from Page Six makes no sense and sounds massively exaggerated. I can understand, hypothetically if Zac cared, that he might use his young fans as the most sympathetic reason to ask for them not to be published. But endgame, I just can't see that he'd really care they are out there. But fans know he's no saint and he's done other 'embarrassing' things (condom drop?) and dealt with it fine.
I can, however, see that he'd want them noted for what they are, which is filming... and I'd totally believe that he'd be smart enough to guess that paparazzi would be happy to leave out that fact in order to increase the value and salaciousness (especially if the papz caught the actual scene, lol). So when they noticed they were being photographed, someone went out and insisted that fact was noted. And the paparazzi decided to salvage what they could and Page Six is the result. So while I think whatever happened was to minimize brouhaha, they only succeeded moderately. Though maybe that's all you can hope for.
p.s. i clearly spend too much time thinking about these things.