My CX account is by default linked to Gmail but when I bought the ticket, I also input my Outlook email and my chinese phone number. When there was a slight schedule change, the notification was sent to all the addreses and phone numbers I had put in during the reservation process.

Honestly during my recent trip, I only needed the VPN occasionally for the aforementioned chat with social media. But to each his/her own I guess, I just try not to put all my eggs in one basket like Google services.