Trust me, I‘m bemused as well. I mean, the Romantics who are listed are an interesting bunch as well, but the connection seems to be this: Bettina von Armin, born Bettina Brentano, was one of our liveliest female writers, but also the Goethe fangirl to end all fangirls. She started a friendship with his mother. After his death, she wrote „Goethe‘s correspondance with a child“ (meaning herself), which is basically RPF with Bettina/Goethe as the main pairing. (How do we know it‘s RPF? Because while he did write her a few letters eventually, she also used letters he wrote to other people (we have the originals), some of the anecdotes her mother told her, and some stuff from his works. There‘s a famous scene where she climbs on his knees and they start to make out. What her husband, who was already her husband when this supposedly happened and definitely was her husband by the time she published this after Goethe‘s death, made of that literature never learned, but then her husband, Achim von Armin, also had an intense passionate friendship with her brother Clemens Brentano.

Anyway: as far as we know, Goethe for a while was amused by Bettina - he‘d had a mild flirtation with her mother when he was young - and did answer a few letters, but when she showed up at Weimar and picked a fight with his wife Christiane, he cut off relations to both her and her husband (who also was a Goethe fan and had written a „your wife insulted my wife“ letter). Important to know background: before becoming Goethe‘s wife, Christiane had lived with him and their son unmarried for 18 years, to the great scandal of Weimar. Christiane being lower middle/upper working class and having worked at a factory for artificial flowers, she was regarded beyond the pale, and Weimar society was much disgruntled when they finally had to receive her as Frau von Goethe. When the Cristiane/Bettina fight happened, everyone other than Goethe sided with Bettina and said it must have been the fault of that vulgar lower class woman, of course.