The buying and selling is actually fine, what fraudsters prey on are irreversible transactions. So specifically crypto withdrawals and transfers are the issue, here. PayPal is not enabling this functionality. Buying, selling, shopping, and possibly deposits if they can swing the regulatory compliance bits. All of this is completely reversible if PayPal finds that it was done fraudulently.
The only concerning part is "shopping" with crypto, and that's likely going to be restricted to merchants that already have a business agreement with PayPal. Under the hood it need not involve cryptocurrency at all except for displaying prices and debiting balances - instead of showing $XXXX, it shows YYYY_BTC and PayPal has to do figure out the currency conversion price for debiting the customer balance in BTC and crediting the merchant in USD.
The only concerning part is "shopping" with crypto, and that's likely going to be restricted to merchants that already have a business agreement with PayPal. Under the hood it need not involve cryptocurrency at all except for displaying prices and debiting balances - instead of showing $XXXX, it shows YYYY_BTC and PayPal has to do figure out the currency conversion price for debiting the customer balance in BTC and crediting the merchant in USD.