Yes, it is not a hybrid it is a tropical which means it will not survive in cold or cool weather, but I can assure you the seeds will reproduce over and over and the plants you grow will produce hundreds of seeds
I have been growing burgmansia a.k.a Angel Trumpets for over 15 years. You are correct, they are indeed tropical. The basic Angel Trumpets come in 3 colors, white, yellow, and light pink. That being said, they only have 1 "skirt", the multi skirted varieties are bred to add skirts, extend the petal tendrils and develope colors.
Unless the mother plant was cross pollinated naturally and then established the new traits that over years would have stablized naturally, the seeds are not what would be considered "proven". Which means that you can get very different results from seeds from the same plant. The only to get an exact replica of the mother plant, unless proven, is from cuttings.
Mine are all from cuttings which are grown indoors in the cold weather and outside in the summer. I sell these here, in upstate new York and no one who follows the instruction sheet has ever had an issue...It isn't easy, but it sure is worth it!! :)