Thank you so much What confuses me is just the part from Timatic:
"Transiting without a visa is possible for: Passengers transiting through Urumqi (URC) with a confirmed onward ticket for a flight to a third country within 2 hours. They must stay in the international transit area of the airport and have documents required for the next destination." since my actual flight out of China is from Guangzhou 14h25mins later in combination with "Passengers with a confirmed onward ticket for a flight to a third country within 24 hours. They must stay in the international transit area of the airport and have documents required for the next destination. This TWOV facility does not apply at Fuzhou (FOC), Huangshan (TXN), Mudanjiang (MDG), Shenzhen (SZX), Urumqi (URC) and Yanji (YNJ)."

On the other hand there are reports of people also here in the thread, that it worked out well on a similar itinerary and a spanish passport if I remember correctly. I also cannot imagine on the other hand, that China Southern would start a brand new route from Vienna with this kind of routing that would force the majority of passengers transiting through China to get an insanely expensive Chinese Visa just for transit. But who knows...