DUB now complains about the package name example.org. Changing this to example-org IMHO reduces the prettiness of the name (and you have to specify the old executable name separately, slightly against DRY). Given that - is not a valid identifier character in most languages anyway, any change to add dot to the list of acceptable characters in DUB package names?
In any case, the warning message (DUB package names may only contain alphanumeric characters, as well as '-' and '_'.) is a bit misleading, only ASCII alphanumeric characters are accepted. Either the check or the message should be tweaked, no?