The instructions in the link I gave very clearly result in a certificate using 1024-bit RSA. Anyone can download the installer or openvpn.zip from there and check for themselves.

  % wget https://www.privateinternetaccess.com/openvpn/openvpn.zip
  % unzip openvpn.zip
  % openssl x509 -in ca.crt -text -noout | grep Public.*Key
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                Public-Key: (1024 bit)

The vpn-encryption page you linked only compounds the problem, because it gives people a false impression that you actually are providing acceptably strong crypto.

You're giving instructions from our 'alternate' installation method information.

Thank you and have a great day.

Those are the only installation instructions for linux. Plus, it doesn't really matter that they're "alternate" if they're bad and PIA knows it (there have been multiple complaints about this on the PIA forum.)

We have a client for linux as well.

That would only be relevant if you instructed people to use it instead of instructing them to use weak crypto.