A third-party user just pinged us about a possible upcoming incompatibility on the notion that Facbook announced  it would cease support for PHP compatibility in future be pronouncing that "... HHVM will not aim to target PHP7 ..." and "... making Hack a fantastic language for web development, untethered from its PHP origins ... ".
... cherry-pick features and bug-for-bug compatibilities based on need, and we won’t be targeting any specific PHP 7.x version. Our eventual goal is for Hack to have its own ecosystem of core frameworks
... supporting some PHP libraries, we will not be targeting PHP software beyond such libraries after the 3.24 release
Given those statements and WMF's reliance on HHVM as operational platform, does it consequently mean that MediaWiki in future will (can) no longer be installed on PHP7 because WMF will have to use Hack as development language to support its HHVM operations?
Some insights on how WMF will (or not) support PHP7 (or anything hereafter) in future would be highly appreciated.