It's a multicultural city obviously. We went recently and got lost in a certain part of London and asked for help including a bus driver and struggled with a language barrier with three out of the four people if that's what be was getting at. I've not seen his comment tbh.
Like Tinkly said things change though and it's always happened.
In the place I now live the village was entirely white English until they were inundated during the potato famine and in the years after when family came over with many non English speaking Irish (including my family) trying for a better life. Most of the Irish settled here, housing was built and they stayed.
In the early 1900s vast numbers of non English speaking Welsh flooded the area (again my family) for the mines. The coal board built housing.
I would say from talking to people most people still here now are from those people.
The Irish came and we ended up with extra faith schools and an extra church.
The Welsh came, used temporary chapels in a tin hut until they could build their own Methodist churches.
I think there are three in the nearby small town and there were two in our village.
A lot of the English already here moved further out. I'm not sure how they felt about it at the time but the entire makeup of the area changed dramatically.
The same for London.
The same for parts of Manchester which were areas of high poverty but now are being filled with expensive luxury apartments.