Apple¹ and Mircosoft² are doing the same. Additionally anything that uses Chromium's trustlists (Vivaldi, Electron, etc) will also distrust old Symantec & co's certs.

1: https://support.apple.com/en-us/HT208860 2: https://knowledge.digicert.com/alerts/ALERT2562.html

EDIT: Its also worth mentioning that this isn't just limited Symantec certs but also will include GeoTrust, thawte, & VeriSign certs. Symantec's cert business has now been taken over by DigiCert so there is a means for valid reassurance.

EDIT2: Also it will effect RapidSSL. Totally forgot about them.