The name 'Polkadot' already refers to a chain. Are you suggesting that once Plaza is (assumedly one) specific chain, that it takes over the name from Polkadot? Or that Plaza includes Polkadot in its name (like 'Polkadot Plaza' as opposed to 'Polkadot Relay Chain') ?

Having a system chain competing with Polkadot's customers (Moonbeam, Astar, Hydration, etc.) is a bad idea, in my opinion. It's just a workaround for the severe issues Polkadot has, such as poor UX. These issues have contributed to the mediocre success of DeFi-related parachains.

However, for the first time ever, I agree with Giotto. If we have a smart contract system chain, it should carry the name Polkadot, e.g., "Polkadot Smart Contract Chain" or something similar, not Plaza. The Polkadot brand should be immediately recognizable, and its success should be immediately attributed to DOT.