I have been an avid user of Coinbase for quite a while, and I am definitely eager to see what other cryptos they choose to add. Although I do worry a little about their shady practices in regards to insider information (like we might have seen with the BitcoinCash surge and 'crash'), they have been mostly reputable and consistent. There has been so much buzz and bounces with XRP and I would love to see the price of it increase exponentially, but I will remain patient and realistic in the hopes that Ripple will return to the $3 zone.
I also agree with you that any new crypto that gets listed on Coinbase will definitely see a significant increase in its price...at least for a little while prior to stabilization.
-Respect