You could pronounce this any way you want and I'd still love it, it's so pretty and because of its many pronunciations it would still sound pretty if people got it wrong, so I don't think anyone could complain if this was their name and it was forever being said wrongly.
Alaia is such a beautiful name! I love it. Alaia sounds literally joyful and I think it ought to be used more often. It's a gorgeous and vibrant name. I like names of that sound - like Amaia, Maia, Gaia.
The meaning of joy in Basque would be: Alaitasuna, not Alaia.
[noted -ed]