3rd Interstellar Comet Just Formed a Bizarre Tail and More Updates

So if our sun is among its first encounters, for it to be so covered in materials that its not lost yet until now... I'm imagining a kuiper belt round a very early star, gets dislodged, falls in, and spends a long time in a wide orbit, with a big Jupiter in the mix, falling, accelerating, but not coming close to the star, then being bumped out by the large Jupiter to cruise the black until it meets us. I'm trying to parse how it didn't lose that material in its own system. Are my assumptions reasonable? Have I understood the basics?