They haven't been cut, they're both way too marketable in Japan for them to be cut. Cutting either or both of them would be like the UFC throwing away money.
And Sexyama was scheduled to fight Alves or Bahadurzada (I forget which) before he injured himself.
I don't think Kid Yamamoto's been cut, but he might've been and the UFC just hasn't announced it yet. He's in the UFC's roster still, so that's a good sign. I think he's just focused on coaching right now; his biggest disciple's that Kyoji Horiguchi dude, and he's been tearing shit up in Japan right now, and it looks like Krazy Bee's doing pretty well as a whole, so he might just be focusing on that right now. It sucks how Kid Yamamoto's career has gone as of late... he just wasn't the same fighter after he tore his ACL, and because of that nobody that became a fan of MMA afterwards has been able to see him at his best. First impressions are important, and it just sucks that for a lot of people, myself included, the first impression was of him being 1-5 and, despite having moments of light in each fight, looking bad and losing pretty decisively each time he fought, and just generally not looking like he would've looked a few years ago.