The fact that Oxford Dictionaries Online provides a single definition of resettle is quite misleading, since the word can actually be used in a number of senses. A better treatment of the word appears in the full Compact Edition of the Oxford English Dictionary (1985), which begins with this:
Resettle, v. Also re-settle. To settle again, in various senses.
In other words, any form of the word that conveys some sense of the idea "to settle again" can be rendered as resettle or as re-settle. The decision of whether to hyphenate or to close up the word is thus a matter of style preference—your own or your publisher's—and not connected to a generally understood difference in meaning (as might be the case with, say, recreation and re-creation).
In general, the tendency in U.S. English (and perhaps in British English, too) is to dispense with hyphens after prefixes like re- except in instances where a clear split in the meanings of hyphenated and unhyphenated forms exists. No such split exists here, notwithstanding the contrary inference you drew from Oxford Dictionaries Online.