I think the OP confuses feudalism and manorialism.
Feudalism defines the institutions and customs that framed bilateral obligations (namely, between a suzerain and a vassal) especially a mutual support.
In the largest sense, it also defines the society based on these and the hierachisation of honors and power defined by a warring social-class (at least in its social justification), decomposition of public authority and property as
honores and
beneficii (very roughly, political power and territorial revenues) became mixed in the Carolingian period.
By the XVIth century, it was moribund in Western Europe, as the royal hegemôn in most exemples was enough to enforce a public rule within all the state, with relations between a king and a powerful vassal not being personal and customary relations, but court-to-court, with the notion of public (monarchical) service being dominant.
Manorialism is more of a social-economical concept. While associated with feudalism, it's more ancient and pervasive : it's the ensemble of ownership (direct or eminent) on which an elite (not always nobiliar, far from it) percieves revenues (direct, but increasingly fiscal).
What if America was colonized with a different hands off approach? With the european rulers as the liege lord of local lords that took over native kingdoms like the aztec one or built their own settlements.
It was what, roughly, happened in
French Canada IOTL, partly out of customs, partly out of the relative weak royal and french interest on the region. Technically, a royal edict made Christian natives eligible to be considered as French ("as natives of France") but it never went really far.
I think the biggest problem for this would be the financing of the starting expeditions since the new lords cannot uphold any independence if their dependent on the european kings.
Medieval economy was increasingly monetarized since the
XIIth century. (To the point the discovery of Americas by Europeans allowed to prevent the worst of a looming monetary starvation)
https://en.wikipedia.org/wiki/Renaissance_of_the_12th_century
Loan and financialisation of agricultural production was really, really important at this point, so financing isn't the problem : it's revivifying a political concept out of the blue that would be.
Remember that Cortez' expedition, for exemple, was illegal and made against the governors' whishes. Because Cortez managed to conquer Mexica, it was passed over but not before he had to split the regions in latifundar exploitation under royal supervision.
Wasn't Spanish colonial rule quiete feudal ?
Not in the more precise sense of the word : rather a mix of manorialism and plantation economy as you had in southern Spain and Atlantic islands since the XVth.