Been heaps of info regarding it on various Thailand Facebook pages, Airlines probably don't care because if you forget or don't do it then you do it on arrival and delay your exit from the airport.
Non O 90 days from Thai Embassy Australia. Then if you can meet financial requirements you can get another year and keep getting year after year if you keep meet the requirements
Note: After the first 90 days and on extension of stay to leave and come back you need to buy a multiple entry permit.