According to ChainCatcher news, the proposal to deploy Aave V3 on the Ethereum mainnet has been released and voting will begin within one day. The proposal shows that the initial version of Aave V3 will be online with lending pools for seven assets: WBTC, WETH, wstETH, USDC, DAI, LINK and AAVE.

Additionally, Aave V3 will be redeployed rather than upgraded from V2. (Source link)