I am travelling with southern china to Europe soon.
Originally my flight would land in Guangzhou at 6am and depart at 11pm the same day. That was cool. Would give me time to sightsee .
Recently my booking changed and I am leaving Australia 12 hours earlier so I’ll arrive in Guangzhou at 6pm and fly out 11 pm the next day.
Questions- I have heard that when there is a stop over for more than X hours then the airline would provide accommodation, as I booked through aunt Betty then would this still happen? Or should I book my own accommodation?
Thank you .

I think you should be able to get the free accommodation.
We booked through BYOJet, which is actually the same company as 'Aunt Betty', and it worked for us. If you go to the China Southern Airlines website and enter your ticket details, you should see a “Book Free Accommodation” button.
The hotel provided was 'Southern Airlines Pearl Hotel'. The default booking is usually a twin-share room. If there are two of you, just enter both ticket numbers. Otherwise, you can pay a little extra to have the room to yourself — I think it was around $30–$40 extra.
We actually just completed this flight last week.
The hotel is about 10 minutes from the terminal. After arrival, once you’ve passed customs and collected your luggage, go to the transfer counter near Gate 50. Just note that this is 'not the boarding gate'— it’s the terminal gate area. Also, the transfer counter is 'not the check-in / boarding pass counter'; it’s located in the main arrivals hall.