Most likely because there isn't any. Apparently, Hatutu was never settled in the first place. As @Fred pointed out, there appears to be no good reason to evacuate Hatutu, and my google search attempts failed to turn up any reference to any population at Hatutu except this exact thread.
In fact, Hatutu was already uninhabited at least by the time of European contact. Early European explorers noted that there was no sign of humans on Hatutu except for temporary expeditions by islanders from elsewhere.
[Eienne Marchand] made no mention of sighting any evidence of human inhabitants on either Etiao or Hatutu. However, in 1798 Edmund Fanning reported seeing a number of "smokes" on the latter island ... probably fires of temporary occupants, since Proter noted in 1813 that both Hatutu and its near neighbor, Eiao, were visited annually to collect the tail feathers of tropic birds.
- Ferdon, Edwin N. Early Observations of Marquesan Culture, 1595-1813. University of Arizona Press, 1993.
As you've noted in the comments, the archipelago was considerably more populated at the time. Nevertheless, none of them settled on Hatutu beyond seasonal trips.
The reality is that Hatutu has very little going for it in terms of human settlement: it a tiny island with no dependable source of fresh water.
[T]he small island of Hatutu (three miles long by less than one wide) [is] separated from Eiao by a channel three miles wide. Because no readily accessible water exists on this island, no animals have been introduced, and almost no economic plants are to be found.
- Pacific Islands Monthly, Volume 36. Pacific Publications, 1965
Due to their location, the Marquesas Islands in general are uncharacteristically dry for tropical Polynesia. It is no coincidence that all inhabited islands in the archipelago has elevations over 1,000 metres. At these heights, precipitation could be captured relatively reliably by the island's topology.
The elevation of Hatutu is only 404 metres, in contrast. Unsurprisingly the island looks rather brown and almost barren, paradisaical rumours notwithstanding. See for example this photo of Hatutu's coast hosted on Google Maps, and also:
Given the above, the most reasonable conclusion is that Hatutu was never inhabited to begin with. There was no population to evacuate and accordingly no one to return.