That's not how PayPal's "bitcoin integration" works. All it is is a partnership with bitpay, where if you're a paypal digital merchant (doesn't sell physical things), and you also have a bitpay account, you can link them.
So someone buys something from you, sends bitcoin to bitpay, bitpay sends actual money to paypal, paypal takes a cut, and gives it to you.
Before you would just use your bitpay account to get actual money, and paypal wouldn't get a cut.
I think the reasoning for a spike isn't anything to do with the actual details of the implementation. The spike in demand is caused by an existing legit payment company that is widely known and used saying: "We think Bitcoin is important and interesting enough to do something with.". This implicit endorsement draws in new buyers, gets more speculators buying, etc.
So someone buys something from you, sends bitcoin to bitpay, bitpay sends actual money to paypal, paypal takes a cut, and gives it to you.
Before you would just use your bitpay account to get actual money, and paypal wouldn't get a cut.
The PayPal partnership is silly.