I have installed that template QS on my hosting but I don't see any suspicus content inside. I even used Joomla Firewall to check code after Joomla update. So I don't know why Google thinks in a different way. Maybe for its algorithms demo content is "bad" somehow. Unfortunately, nowadays large corporations are the oracle of truth for people. But it's just a script, today it works like this, tomorrow it works differently. You can't always believe them. So please test it on localhost etc.
I informed Google that site is OK, I hope they will fix it soon. Do it as well. Here is link >>