I wouldn't like to seem them completely decoupled from the normal Great Person generation as it would really weaken the Garden building as well as Austria's UB.
Already Generals, Admirals, and Prophets are separate from that mechanic. To also remove Artists, that leaves only Engineers, Scientists, and Merchants (which would now be less than half the Great Person types, so it can hardly be called + Great Person generation).
Actually, if you think in terms of Wonders. If a wonder still gives great person points to a type of Great Artist, those points work through the normal Great Person generation mechanic. If they remove the Artists from that pool, they would have to change how Great Person points function or have all the Wonders that currently give Great Artist points give to either an Engineer, Scientist, or Merchant.