This is an exceedingly complicated question that would require pages and pages to answer properly, but the simple answer is that while there were undoubtedly people who were happy to become part of the United States, historians have traditionally painted the Creoles as being resentful of the transfer.

We do know a couple of things (all of which pertain largely to Basse-Louisiane; I cannot speak for the inhabitants of Haute-Louisiane, who were much fewer in number) that may help shed some light on this issue:

1.) Napoléon effected the transfer without seeking so much as a single Creole opinion.

2.) There are (perhaps exaggerated) accounts recounting the Creoles' weeping in the streets when the French flag was lowered in the Place d'Armes and replaced with that of the Americans. Certain members of the élite, not only in New Orleans but also in the Attakapas country, had also benefited from a close relationship with Spanish government officials such as the Marquis de Casa Calvo, and they probably resented losing this privileged position in exchange for new officials whom they did not know. (Spain also protested the Sale, but did not have the money or military power to prevent Napoléon's decision.)

3.) After the Sale, Creoles and Americans did not particularly care for each other when common interests (i.e. economics) did not require they get along. (In fact, Louisiana francophones will not refer to themselves as Américains even today, as the term Américain preserves its original connotation as pertaining to the Anglophone outsiders). Many members of the two groups preferred to live apart and socialize in distinct spheres. Almost immediately after the Sale, the first governor, William C.C. Claiborne, attempted to pass legislation to limit the influence of the French language in favor of English. The Creoles did force him to backtrack, but whether the Creoles were resentful or not at the outset, many were to become increasingly so as the Americans continued to install Anglo-American officials in the new political positions in attempts to limit the power of the francophone Creoles.

4.) It has been noted that at the beginning of the War of 1812, the Creoles were quite ambivalent to the conflict despite being nominally part of one of the warring parties, potentially underscoring the feebleness of their emotional connection with the United States. It wasn't until later in the war that the Creoles became more ardent participants.

5.) The Creoles were quite aware that an influx of Americans would possibly spell doom for their culture, and if they weren't convinced of this at the beginning, it did not take long for them to become so. As early as 1819, not even twenty years after the Sale, Américains such as Benjamin Latrobe (who was actually British) were commenting on how "many of the leading gentlemen, when not talking of tobacco or cotton, find it very amusing to abuse and ridicule French morals, French manners and French houses"—and by 1821, newspapers such as Le Courrier de la Louisiane were producing statements such as the following:

"We ought no longer to dissemble, the days of forbearance are over. Our prudence, our patience become every day more fatal to us . . . But let those who are so anxious to found that Babylon well remember that we are the first and the old population of the state, as the Quakers are of Pennsylvania, and that, like them, and our other brethren of the Union, we shall know how to cause our primitive rights to be respected. Let them be aware that we can in an instant annihilate the imprudent innovators who should try to deprive us of those rights."

TLDR: While we speak of an extremely complicated phenomenon that likely produced a variety of emotional reactions, the relationship between Creoles and Americans has traditionally been portrayed as grudging at best, if not openly antagonistic, and we can assume that numerous Creoles were unhappy or furious with the Sale of Louisiana to the United States, with others to become so in the aftermath.

Re. returning to France, this was the turn of the nineteenth century, and most Creoles had no real means of returning to France even if they wanted to—and besides, most of them had nothing in France waiting for them. There were always members of the Creole élite who spent significant time in France as well as Louisiane, such as the Baroness de Pontalba, but this was not representative of the majority of the population.