There are times where coinbase blog will announce that coinbase is continuing to explore support for digital assets (though it's not a guarantee that they will list those projects), and those are often covered by a crypto media like The daily hodl as an example, I'll put some linked examples below :
We know about that dude but the problem is how can we accurate predict which coin that will be listed on coinbase? we can jump together into the coin to get the short term impact caused by the listing.
I think that OP was looking for the solution or at least a way to know which coin that has a very big potential to be listed on coinbase.
I think it can be traced through the token holders.