For example - Uncle John went shopping. Is Uncle John an MWE?
From the definition, the words have to belong together and form another meaning to be multi word expressions. But Uncle and John convey two completely separate meanings.
One difference to an MWE is that Uncle John can be translated to any language which knows a word or a phrase meaning Uncle and a name close enough to John without any difficulties and in any context.
A real MWE like "automatic car" can not so easily be translated to another language. Mostly because we can have different interpretations - does an "automatic car loader" load automatic cars or automatically load (the batteries of) cars?