Don't know where you get that from. The squad has several players in it that didn't play SOO this year and it has always been the same. The ARL picks the national team and the State leagues pick the Origin teams. They are not bound to each other in any way when it comes to player selections.
I never said they are bound, but if you don't represent your state, the odds of you representing your country are slim.
As for those who haven't played origin this year, it's likely that form improved over the year, or this year was a breakout year for them - and this is common for teams who progress well in the finals, which is why the team is dominated by Storm players.
Thaiday falls in neither of the above mentioned categories.