I can just see Brian Armstrong saying something like, "Oh man sonofabitch that ponytail fuckwad Powell's already added Monero ahead of us??? Well, I'll show them who's boss! Let's get both Monero and Dash too, launched on our site together!! Yeah!!! That's the ticket!!!! Hahahahahaha"
I have always find very strange Monero was on very few exchanges, it was many others concern as well, but now on bitfinex and kraken with fiat pairs the danger of centralization on a single domain was mitigated, I don't believe just being on more exchanges brings true demand, it just helps to distribute the incoming flow better.
Game theory says thats the most probable outcome. Still I doubt dash will get anywhere close to Coinbase with cobble as director of engineering, he is very aware of its pitfalls.
it also helps to mitigate a total "loss", imagine all those coins that went down with cryptsy and never came back alive.