yes, it defaults to auto upgrade when you do a iOS update. The subject has been addressed here a bizzilion times to turn off the auto update feature. I too have fallen prey to the same screw up.
last night there must have been bad mackie karma in the air, I finished sound check everything smooth as silk, even had a good new verb setting happening.
Turned on my other iPad and hit the wrong sync button and wiped out my settings. had to redo entire sound check with 5 minutes to go before start. Luckily a small show without guitars being miked.
Only had to deal with drums, vox, bass and quickey monitor test.