The announcement is made official by Avast in a blog post as it says updates for antivirus products on Windows XP and Vista would no longer ship as of January 1, 2019, though the company also adds that virus definitions would continue to be released.
For XP users it is regrettable news according to Softpedia, no technical support services are to be provided for users of the XP platform, meaning bugs and other issues experienced by the antivirus wouldn’t get an official fix. In other words, the existing versions of Avast will run on Windows XP just like before, but new features would only be offered in builds aimed at Windows 7, Windows 8.1, and Windows 10.
Avast users get to update their Windows operating systems to the latest version of Windows 10 not only to continue enjoying the newest Avast security upgrades but also to eliminate the probability that the vulnerable older system you are currently using will get exploited. – Avast
Presently, the latest version of Avast for XP/Vista is v18.7, which must be a Win7 system after 18.8. In addition, forum users broke the news that Avast plans to release the final version of XP/Vista 64-bit in November as a complete stop.
Despite the mentioned January 1 deadline, it looks like the end-of-support for Avast on Windows XP will actually happen much sooner.