Joking about residency is fine.... I do find the mocking of names a bit off though. As if everyone in Scotland has to be called Hamish Mactavish, and only England is allowed "foreign" names.
To be fair he didn't mock names, he suggested the names implied British/Irish heritage.
Wouldn't be mocking to say someone with Traore as a surname could have Malian heritage, , someone's surnaame ending -sson having Icelandic hertiage or someone with a million vowels in their surname ending in -nen has Finnish heritage