If they were Pokemon fans wouldn't that mean they would pace themselves, check every building, talk with every character, find every Pokemon, pretty much check every nook and cranny of the game and not trying to rush through it? Probably moreso if they played the original RS as they'd probably want to see the differences and what's been added/removed from the remakes.
And if one person got it early I wouldn't be surprised if others did too, however they'd probably keep their identity secret. As to why there isn't a lot of updates if there at leaks, well I don't know. For the one on 4chan I would argue they probably posted there to annoy the people there, if they were serious about reporting new info I'd imagine they'd go onto reddit or maybe Serebii's or Bulbagarden's forums. As for others, maybe they just want to enjoy the game and not want to feel obligated to keep people updated on their playthrough. The game is going to be released next week anyway, so it's not like they'll discover anything we won't in about a week's time.
I'm personally sweeping this who leak deal under the rug, it'll help keep some surprise of the game for me.
Redeemable Master Ball:
Yeah, I think the time has passed when the Master Ball was considered the ultimate item. Unless there's a roaming Legendary or a Shiny it's just a trophy as everyone would either use Ultra Balls or Dusk Bulls on stationary Legendary Pokemon. I'd argue that having it for 100 BP like the Ability Capsule would be good enough as pretty much the only reason anyone would want one after the story and catching the Legendaries is if they happen to run into a Shiny Pokemon.