On the one hand, you shouldn't discriminate inheritance by sex. On the other hand... everywhere else does, in favor of boys, so it was nice to have SOME places that favored girls. For global balance.

Even without this change the maternal uncle always had a lot more power than you think. When people here talk about matrilineal societies they always dismiss, or ignore the maternal uncle influence. For example even thought the woman is the “owner” of the land. He actually has the final decision on what she can do with it.

Men can hijack the matrilineal system for their benefit, but instead of father it is the uncle who does it.

Hypothetically women could do something similar with patrilineal kinship.

I wish this article shared more of the history behind this tradition. I found this BBC article which seems to indicate the society became matrilineal as a result of men dying in wars.

As warriors who often battled with other groups for land, Khasi men often went down to the plains for clashes. During those battles, some men died. Others settled for a new life in the plains. Left without their partners, Khasi women would remarry or find other partners, and it often became difficult to determine a child's paternity.

"Society might have labelled those children 'illegitimate'," said Passah. "At some point, our ancestors thought that they didn't want this slur on their women or children. So, they decided that children should have one last name: the mother's."

The reason the youngest daughter assumes the inheritance is because she is committed to the duty of caring for the dying parents and their property:

Traditionally, Khasis live in close-knit extended families or clans. Since children take their mother's last name, daughters ensure the continuity of the clan. Daughters have the liberty to live in their ancestral home or move out, except for the youngest daughter (called ka khadduh), who is the custodian of the property. Even after her marriage, she never leaves home. She looks after her parents and eventually becomes the head of the household after her mother's death.

It makes sense, therefore, why childfree or only-son families would want to be able to pass on their home to whomever will end up caring for it, whether sons or some other family. Maybe some daughters do not want to be tasked with the responsibility of eldercare and her liberation is in seeking career and home elsewhere.

However, we can't underestimate the influence of patriarchal society's infectious impact.

With colonisation and missionary education, however, some Khasis left their villages, looking for work in towns. When nuclear families emerged, the knis' power began to decline, and while villages still follow the traditional matrilineal structure, in some urban Christian families today, fathers are the head of the household.

I also think we should be cautious to associate "matrilineal" with "women-led" -

The traditional matrilineal society has always kept women out of the larger decision-making process in social institutions like the village council.

Regardless it sounds like women have significantly more rights and authority than in many close regions and I'd love to chat more with women from there about their experience and thoughts.