Lolwut ? I want the drugs he's on...
Pakistani got the bomb in the 1990s and they genuinely are both a republic and a majority muslim (I'm not sure the exact definition of "Islamic Republic" he's using.)
On the other hand a single digit percentage of the UK population are Muslim (6%), and dude, we've been a monarchy for all bar a couple of decades of the last 1500 years.
The Muslim thing is less a worry than trying to pretend one of the longest running monarchies around is a republic, I mean it's just delusional.
In the last millenium England has only been a republic for the couple of decades in the 1600s when Cromwell took over and executed the king. Scotland has been a monarchy the entirety of the last millenium, Wales has been under the English monarchy since the Normans finished slaughtering them in the 1300s.