The project I am working on has quite some classes defined in the global namespace.
When adding a wildcard definition for these classes, not only those classes are matched, but also matching class names in any namespace.
This is quite unexpected, since the documentation states:

the wildcard does not match across namespaces

For example:

return [
    'Job*' => DI\autowire()->method('foo', 'bar'),
];

will call foo('bar') on class JobDoSomething, but also on class SomeNamespace\JobScheduler, which is not in the global namespace.

I am unfortunately on version 6.3.5, because PHP 7.2 ... But the code for matching the wildcard (regex) looks to be equal in both 6.4 and master.