I’d argue that shortened names aren’t pronouns. Like, “Bob” isn’t a pronoun after all. But that’s a cool idea nonetheless.
Counter-argument: the only two reasons why “Bob” isn’t a pronoun are a) because English has other pronouns and b) because not every name has a form that’s short enough to use in place of pronouns.
I would say it’s fully plausible that a language develops proper pronouns (with case markings and everything else you would expect) based on a rule that works with any name. As an arbitrary example, a Robert, Robin, Ronald and Rocinante might all use roki for the nominative case, ros for the genitive case and ron for the accusative case. In the absence of other pronoun systems, that would be indistinguishable from what you imagine as pronouns. Add a few centuries of sound shifts and you get something really interesting.
Counter-argument: the only two reasons why “Bob” isn’t a pronoun are a) because English has other pronouns and b) because not every name has a form that’s short enough to use in place of pronouns.
I would say it’s fully plausible that a language develops proper pronouns (with case markings and everything else you would expect) based on a rule that works with any name. As an arbitrary example, a Robert, Robin, Ronald and Rocinante might all use roki for the nominative case, ros for the genitive case and ron for the accusative case. In the absence of other pronoun systems, that would be indistinguishable from what you imagine as pronouns. Add a few centuries of sound shifts and you get something really interesting.