Inventing a new name for something doesn't make it new. The cultural mix of London has been constantly changing over the years, and continues to do so. My Dad grew up in Stoke Newington, which was then characterised by the large Jewish & Greek communities, and he often used both Yiddish (itself a mixture a Hebrew & German) & Greek words. Rhyming slang not so much. I lived in SE London for a while and my neighbours' kids spoke a West Indian patois most of the time. Having lived and worked in a number of Arabic speaking countries, I still find I use Arabic words on occasion!"Multicultural London English" (MLE) by academics -- a way of speaking born from the melting pot of immigrant communities in the capital and spreading rapidly throughout Britain.