Welcome to Android Central! This is how the app launcher looks now. Google is essentially trying to unify the UX of Chrome OS and Android (but not necessarily merge the two). You could always do a PowerWash, which I think will revert the device back to the original Chrome OS version it came with, but I'm not sure if you can prevent it from auto-updating. I'd strongly recommend against that anyway, because keeping up to date with Chrome OS updates is important for security.
You could also try a 3rd party app launcher, like
Apps Launcher (which I use as well).
