I don't think paypal can ended by bitcoin, but both can work together for easy and smart exchange to the bank money, in other word paypal will never end because bitcoin
BTC can work yes agree with paypal for exchange and this has been done by large wallets that are similar to paypal,they have made it easier to exchange from BTC pair to digital fiat and it has long been applied.Its true that paypal still exists to shop but few now use the service.