If you look at Einstein Bagles menu they have

Nova Lox and Schmear (yiddish for smear/spread which is usually cream cheese or flavored cream cheese)on the menu.

I'd say both terms(lox(originally pronounced lacks) and shmear) are sufficiently commercialized that they are common at any bagel place even outside of cities with large Jewish populations.

At least in the US, maybe not in the UK.

Also note that most lox isn't actually lox. Traditional Jewish Lox is brined salmon belly. These days lox usually refers to any smoked salmon, especially less salty types then traditional lox