Capt. W could as easily have died the moment he left Anne, of course. Disease, accident or battle claimed captains as well as seamen. JA is setting us up for wondering just what did become of him, I think. Is he still looking to make his prize money? Has he attained a high command? She builds the suspense quite well with the bits you've identified, asking us to reserve our judgment until we have more information. The reader waits to find out which way life has taken him, hoping that later chapters will give more insight.

Good thoughts and insights, Jan.