Some very useful ideas in this article, and some very dangerous ones.
Bullying and dominance are possible social strategy sets present and dominant in many cultures. I see no ethical basis for conserving such diversity.
Similarly I see no ethical basis for conserving any cultural modality (in so far as such cultures impinge on the freedom of individuals acting responsibly).
Cultures are a very poor mimetic analogue of a species.
Individual human minds are much closer analogues to mimetic ecosystems, within which exist many mimetic species in complex associations.
Cultures, in as much as they have form and structure seem to me to be mere shadows of the complexity within the individuals within a culture, and say more about the major modalities of sets of ecosystems present in the individuals with those cultures.
Once individuals pass second level abstraction, then communication with outside agents becomes improbable, with each successive level of abstraction attained by such individuals reducing the probability of communication by further orders of magnitude. Even third level abstractions are almost impossible to communicate, by the time one gets to 10th level abstractions, it is unlikely that anyone on the planet is likely to get the message transmitted.
Our world is already post cultural, in many very significant senses. The proportion of individuals within any particular cultural that are post cultural can vary substantially, both between cultures generally and geographically or socially within cultures and subcultures (in as much as those terms have any meaning in such contexts).
There are many conventions in reality that are arbitrary, and it only matters that there is agreement, like which side of the road to drive on. Not having such conventions imposes a lot of risks and costs. Adopting such conventions (protocols) can significantly reduce risk and increase efficiency. In that sort of context, there can be some value in culture, and there can also be significant costs as technologies evolve but interfaces remain static (I have one computer board where most of the board is taken up with interfaces, the chips that do the work are tiny). Rapidly changing technology can demand rapidly changing standards. Some can find that difficult.
And when one is exploring new territory, such protocols are not normally required. Anyone doing such explorations accepts that risk is a part of the process, and traffic or interfaces are unlikely to be significant issues.