This does, effectively end support for XP, as the latest version available for that OS is 49. Users will still be able to use Gmail until the end of the year, but it is time to start thinking about upgrading or retiring those. Also, there are currently 28,447 Chromebooks that are still at 53 and below across the district. Now, would be a really good time to get those updated, as PARCC testing also requires an up to date browser.
Instructions for how to update Chrome by OS.