For scripts installed by Softaculous, would be nice if there was a system script that checked the highest version of PHP supported vs the versions on the server and it the auto-updater updated the individual scripts, it would move the PHP to the highest version.
We will review this internally if it is possible to build such a tool.
Even if we are able to build such a tool in case of WordPress a site could be using numerous plugins and each plugin could have different compatibilities which can break sites.