Why is Whatsapp requiring a new app version be downloaded?

The Whatsapp on my Macbook is greyed and labeled (old).  It is requiring me to download a new app.  This requires a QR code using my phone, but the app for QR is requiring a new app.  I just saw a social media post regarding QR codes that after scanned infect your phone and infiltrate your accounts.  I then researched this post and found that their have been FBI warnings regarding QR codes and one was requiring to go through an updated app.  I love using Whatsapp, but I when I go onto their website to ask a question, I get an error code that something went wrong, try again later.  When I try again later, it still happens.  My questions:

1. Is this a legitimate app version update?

2.  Can I update app without the QR code?

3.  Can I archive my "old app"?  (So many pics and videos I continue to revisit.)

Thank you