It still has to be passed by the senate, then approved by the King and the put in the Royal Gazette then after that have to wait another 90 days until it’s law, so after all of that possibly the latter part of the year.
There is no such thing as a visa on arrival for Australian passport holders, you will get a 30 day visa exempt stamp free of charge on arrival with the capacity to extend it one time only for another 30 days for 1,900 baht