I found following comment on apple suport "Apple support told me to always do updates through iTunes and connected to my computer, not direct using wifi. Chance of corruption is high" Is it true?

I have always updated via iTunes & never had any problems of the like reported on these forums, minor ones which were corrected by a reset or turning device off then on yes.

From experience and these forums you are certainly MORE likely to have a problem if you update via WiFi.

I've been updating over wifi for years without a hitch. Honestly, I cannot remember the last time I did an update via iTunes, but it was at least 2 or 3 years ago (my iPhone 4 it would have been). I do always check to make sure I have a recent iCloud backup in place, and I make an iTunes backup over wifi before updating iOS. While I'll usually plug in the device to run the update over wifi, a few times I've also gone ahead (with a full battery) and done it on battery. But regardless, I've never had a problem with wifi updates (and have been doing them since at least iOS 6, or earlier, although I do remember being a bit paranoid about doing it originally when it the option came out with iOS 5 so still used iTunes for awhile then).

Bottom line is anyone may have issues with any update, wifi or via iTunes, but most people do not have any problems with either. Remember with every update nowadays, there are tens to hundreds of MILLIONS of people updating, so the uproar that a few seem to make on the internet with issues is really only a tiny fraction of total users. Quite likely about the same proportion of people who have issues with every OS X update, every MS Windows update, every Android update, or even every Ubuntu or other Linux update/upgrade (and yes, with every one of those systems, you can find forums and web sites with people with FUBAR'd updates).