Adding another thing to try.
I have an iPad that had sound for iTunes and movie playback only, and all other apps, including games, had zero sounds after the update. I did have lock sounds, but no keyboard sounds even though those were both set on.
I rebooted several times, did the toggle on the mute switch as suggested and nothing.
I went into the "sounds" area on settings. Toggled both the lock sounds and keyboard sounds OFF, did a reboot, then went back in and toggled both lock sounds and keyboard sounds ON. This brought back not only my keyboard sounds, but also the sounds on all my games and apps. It's worth a try if the other things don't help.