this has become a common question over the past few days.
theres nothing to worry about.
OpenFrameworks is just a c++ library. It’s not a compatibility layer or a cross compiler. Apple has nothing ruled against c++ libraries and if they ever did it would be a huge insane disaster because it would effectively ban anything that apple didn’t explicitly implement (twitter, cocos2d, etc.) e.g. it would never ever happen.
It could happen, it’s quite likely they will introduce a new clause: "you are not allowed to use any library - even if C++ or even Objective C - which makes your life easier, and is open-source and generally aimed at helping communities develop better applications. "