After Gregor’s death, one by one, each member of the rest of the family will turn into giant cockroaches due to stress and isolation.
We do not have an In-Universe explanation for why Gregor becomes a cockroach in the first place, and we never will. However, from a literary standpoint, the connection is made between being a cockroach and great emotional strain on the one being transformed; Gregor acts as the family punching bag that they don’t treat very well even before he became a bug, and afterwards treat him even worse. Perhaps, in this world, people who undergo extreme stress transform into cockroaches (and perhaps other kinds of animals), which would explain why no one in the story is shocked by Gregor’s change in appearance. Ironically, this also means that the most likely way to cure Gregor would be to ‘’alleviate’’ his stress by caring for him, but his family was too prideful to do it and embarrassed by his plight.
Grete is now the family breadwinner, but with Gregor gone, her parents will undoubtedly begin treating her the exact same way they treated him, until, a few years down the line, she will undergo the same metamorphosis. In this case, her parents will similarly neglect her until she perished as well. Then, with no one to take care of them, the parents would be forced to either fend for themselves financially (which could kickstart a transformation on the one working) or possibly go homeless (which could happen to both).
The story is about Grete Samsa, a trans woman with the deadname Gregor, and her coming-out.
Pretty far-fetched, but could be. Gregor lived more for everyone else's sake and was a facade kept up for his family and society, and Grete was always also there for most of Gregor's life. Grete was mostly herself when she played the violin, since it was seen as feminine by everyone else, what is the reason why Gregor is pushing Grete's skill so much. In the end, Gregor, a false identity literally "bugging" her, may finally die, and Grete steps into a new life as a transitioned woman.
