This is what the author is foreshadowing in this passage. In the passage, the man offering the monkey's paw tells us about the fakir and the spell that has been put on the paw. He also tells us that the fakir's intention was to show how interfering with fate could lead people to tragedy. Therefore, it would be reasonable to conclude that the White family will in fact interfere will their fate, and that this will lead them to tragedy. It is very likely that Mr. White and the rest of his family will come to regret any wishes they make on the monkey's paw.
