There are times where coinbase blog will announce that coinbase is continuing to explore support for digital assets , and those are often covered by a crypto media like The daily hodl as an example, I'll put some linked examples below :

https://dailyhodl.com/?s=coinbase+asset

https://dailyhodl.com/2021/03/21/coinbase-exploring-support-for-43-altcoins-after-addition-of-crypto-asset-cardano/

https://blog.coinbase.com/coinbase-continues-to-explore-support-for-new-digital-assets-2c5b84813fcf

https://blog.coinbase.com/coinbase-continues-to-explore-support-for-new-digital-assets-37c9737546b0