According to Australian law; No, no they don't.
I would think the biggest impact they would have would be habitat displacement, competition of food source and and adverse impact on eco-chains(ability to take bigger prey key to local biocycles ect.)
Law does not always mean right or well thought.
I have been wondering about the actual implications for awhile now, my views have changed abit, but I am currently sitting on "very little impact"
0.5% of Aus is Rainforest (assuming they are all suitable for boas)
We have large pythons here anyway.
If they are even able to compete, they would have to compete with our locals who been evolving here for xxxxx years in their own habitat. Same food, same predators while having to adapt to their new home.
I just don't see boas having anything "special" to out do our natives. Mind you I don't know how the live birthing aspect would change the game? Similar time from ovulation to hatchlings, but unsure if external is less of an advantage or not. Our native's current system seems to be doing the job though.
Always open to more input!