Google really, really likes changing its SMS app's name. First called 'Messenger,' it was renamed to 'Android Messages' in early 2017, likely to avoid confusion with Facebook's extremely popular Messenger. Now the name's been shortened to just 'Messages' on the Play Store listing. What a world we live in.
How it looked before today.
To be clear, this isn't going to have any effect on the name shown in your app drawer. Thankfully, that was already simply 'Messages'; 'Android Messages' would have been super long and super redundant. Then again, 'Android Messages' as a Play Store listing title was pretty redundant on its own. After all, you can't post any non-Android apps on the Play Store anyway. In short, this is just Google correcting a mistake it made a long time ago.