The “Play” button for game update notifications always remains in English no matter what language you have selected. Everything else on the notifications list is correctly translated into the respective language.
Steps to reproduce
Switch the language on the website to any language except English
Open up the notifications list
Open up the list of game update within your notifications list
Everything else is translated into the respective language except the “Play” button which always remains in English
Adding on to this post, my game titles always automatically translate to Spanish (ones that actually have a translation for other languages with the new title translation feature) when my language is set to English but I did end up setting my language to Spanish to test the new system for fun and then I switched it back to Spanish but I don’t think it fully reverted everything.