I mean, since PayPal already allows the trading of a few cryptocurrencies, then by definition it's already a "crypto exchange".
And I realize that a lot of people are excited about this, but I just don't see why. Skrill has done the exact same thing some months ago, and no one turned this into a big deal so PayPal should be no different.
There's a huge difference though, and that is that PayPal already has 346 million users[1]. While the crypto trading service isn't available for everyone yet, just imagine how much people would have exposure to bitcoin. They wouldn't need to install and register on a separate app for their bitcoin purchases.
[1]
https://www.statista.com/statistics/218493/paypals-total-active-registered-accounts-from-2010/