I think this might happen by end of this year or even later because they just said they have idea to add the ERC20 tokens to their wallet but still no new about when it will happen.
Will coinbase also offer exchanging of erc20 tokens to fiat currency? That would be really great if they did(since I have many erc20 tokens that I want to convert before this year ends). I also wonder though, will this spark erc20 token's popularity to newbies and the public masses as well? If that is the case, then it would really be great for crypto in general(because adoption rate will increase).
If they have added tokens into their wallet means it will also be available for trading as well because coinbase is mainly an exchange.But we don't know that when it will happen and the chance of adding all tokens is also very less because everyday lots of new tokens is getting into the market.