Ironically, adding missing variable names to @param lines increases the amount of errors in PHPStan output:

While there are now less PHPDoc tag @param has invalid value (type|class Explanation of): Unexpected token "Explanation", expected variable at offset 123 lines, PHPStan being able to find and parse types/classes in PHPDoc creates more additional Parameter $foo of method ChildClass::overwrittenMethod() has invalid type wild. errors accompanied by Access to offset 'bar' on an unknown class wild. errors.

Testing a few entries in Diviner, the patch in D25794 literally does not seem to change anything - results before and after are still the same, which means that Diviner is kind of smart in this aspect (and also not smart due to the 404s I get for methods indexed by the Diviner Search but only rendering a non-existing page).