The use of the indefinite article with a proper name occurs often in business or organizational speech-contexts:
We're lucky to have a Bill Jones to get the job done.
The article plus proper noun is used differently there than it is in narrative contexts, where it is typical to find an adjective as well:
A young Bill Jones would soon make his debut at Carnegie Hall.
There is an inherent contradiction in the former combination: it suggests individuality and fungibility simultaneously. It is subtly demeaning. The locution praises Jones while reminding him and everyone in earshot that employees can be replaced, although this message might not be at the conscious level.
I recall reading that, in a language whose grammatical genders included
inanimate, it was possible to insult someone by affixing the
inanimate gender marker to an adjective applied to the person. Do you think this use of the indefinite article with a proper noun functions in a similar way?