The php7 download isn’t available yet because it isn’t in the front-facing page “http://get.pocketmine.net”
This file, downloaded from pocketmine on each MineOS service startup, contains only the following files:
# Temporal build
When the pocketmine devs update this file (presumably because they think each arch is actually ready for prime-time), it will auto populate here. Apparently they feel this way for ANDROID, as you’ll see the webui (right now) actually shows ARMv7_Android, but not yet the rest.
You can, of course, download the files manually, by connecting through SSH and doing the download as instructed by the pocketmine website. You’d then just have to drop the files you manually downloaded (through the script) into the live server directory (/var/games/minecraft/servers/yourservername). This manual bit might be a bit kludgy and confusing, but then it might just mean to wait for Pocketmine to deem their php7 builds ready enough to put in the download script itself.