I think whether to prune or not is probably a moot point. The tree doesn't tolerate freezing weather, so you are probably going to have a tree that dies back to the ground with every harsh winter.
I don't think that instruction means don't prune adventitious suckers off the main rooting system. I think it means when you attempt to lion-tail the tree for esthetic purposes, you should expect a lot of new suckers.
I'd give that tree two years growth, and see how it goes. When the trunks start crowding each other, prune it back to one main stem. By then, it will have a more established root system and will also be somewhat trained for a more vertical growth habit without all the lateral branching.
I would speculate that this tree grows in thickets. When such a tree grows out in an open area without crowding, they spread horizontally more and are more inclined to grow the vertical suckers. Pruning trees of this growth habit just to make an open canopy is going to increase the number of adventitious suckers that erupt.
Perhaps you can make some cuttings and start your own thicket. In 15 years, cut down all the thicket except for the best tree and see how splendid a tree you have grown. Obviously, this is a rather contrarian way to avoid pruning, but it will work.
A less contrarian way: read up on how to prune them. This article discusses your exact problem, and pretty much repeats my advice.
https://www.gardeningknowhow.com/ornamental/trees/jacaranda/pruning-a-jacaranda-tree.htm
"You'll have to remove competing leaders every three years for the first 15 to 20 years."
