TSHEPHO RAPHOLO Thanks for confirming.
I'm summarizing the issue and adding as an answer. Since the Microsoft Q&A community has a policy that the question author cannot accept their own answer, they can only accept answers by others, I'll repost your solution in case you'd like to Accept the answer.
Your understanding is correct. If it is avilable in the region you will be able to deploy. I can see from the screen shot you shared earlier was not showing the GPT-4 in the list.
It is enabled later.
To deploy the GA model from the Studio UI, select GPT-4
and then choose the required model version from the dropdown menu.
If you have any other questions, please let me know. Thank you again for your time and patience throughout this issue.