As announced back in April, all the dev sites have been switched to PHP 7.1.
We are now happy to make the official announcement: on September 5th all the live sites will move forward and get PHP 7.x so that PHP 5.6 will be deprecated. This gives you time to check all the plugins and themes, to make sure everything is 100% compatible with PHP 7.x and if not, to implement the necessary fixes so that everything is functional by September 5th.
You can use the dev sites to see if you have any plugins or themes that need work on ( as all the dev sites are currently running on PHP 7.1), and once everything is in order, you can implement them on the live site.
As per the tests performed, PHP 7.x outperforms PHP 5.6 in terms of better response times so we are expecting better all-around site performance and are happy to be able to give you a better framework for your sites.
Also, as a side note all new sites added on our platform will be using PHP 7.1 by default, as of today.