That is to say, the conditions for the end of feudalism
Medieval feudalities already were going trough a change : the disappearence of servage in western Europe was enacted before the plague, for instance, as well the great urban development and the subsequent starvation crises due to agricultural production not meeting demands.
It might be stressed that, if anything, the importance of religion grew during the crisis, and launched some sort of "awakening" into the population that can be illustrated with the prevalence of Christian names in popular classes after the XIVth century.
decline of the low nobility
If anything, we see the disappearance of many aristocratic lineages at the benefit of middle nobility during the Late Middle-Ages, and these will dominate (as aristocratic lineage themselves) the later periods, socially wise.
, and social changes are not developed.
They were already ongoing since the XIIth century : could be mentioned, for instance, disappearance of serfdom, birth of medieval capitalism, rise of urban freedoms (with or without royal patronage and limitations) and secularization of political authority.
Medieval era as a period of stagnation, including (and critically) socially is a trope since long debunked.
The Black Death may have served as an accelerent on this development, as well with definitive specificites, but it didn't ended Middle-Ages by itself (and many of late medieval concepts survived up to the XVIIth/XVIIIth centuries).
Starvation crises would still happen as in 1315-1317, and generalized warfare in Europe is still pretty much likely.