I kinda expected it...
In 2019 the Microsoft Extended Support for POSReady2009 is gonna end, so I kinda expected that Avast was going to drop support for XP with Avast 19.
As long as definitions updates are provided, it's not gonna be a big deal, especially 'cause there are already many functions in Avast 18 and it's a really complete antivirus.
Hopefully, the latest 18.x stable release will be perfect and bug free, so XP users will have a bullet-proof product for the years to come.
I've been using Fedora, but I also have Windows XP installed in a VM for many tasks that I can't do in Linux.
I've been an Avast Beta Tester since 2013 when I purchased Internet Security and then Premier in 2015.
I'm gonna renew my Premier licence in a few days and my "journey" with Avast is not over yet; I'm just sad that I'm not gonna be a beta-tester anymore.
Thank you for everything you have done during these years! :')