Ok i came to this thread a bit late, but do you realise that 13500 to 8200 years ago the Yangtze river basin was not populated by the Han Chinese. The culture which became the 'Chinese' were from around the Yellow River which is further north. In fact, if you go and read the related wikipedia article regarding history of rice cultivation, it says this:
So if we follow wikipedia, the most likely first rice cultivators are pre-Austronesians. Guess who are Austronesians?

Wikipedia Link

Based on Sunda Theory is the people originated from Pentas Sunda during the last Ice Age.

When Pentas Sunda sunk around 11000 years ago, the people there flee all over the place.

Later the people met with other people.

The one going north met the Inuit/Siberian.

The one going West met the Indians.

The one going South met the Papuan/Australia aborigines.

The one going East met the Islanders which is similar to Papuan.

From genetic and geographical point of view this make sense.

Of course other than the people in Pentas Sunda there are also traces of 'aborigines' that live in the inland which is similar to the Papuan.

Many of the people also have their own version of the Great Flood Legend depicting the sinking of the Pentas Sunda and people fleeing the continent.

What talk you? 4000 years ago China culture was Xia. Go look where Xia is. Nowhere near Yangtze river. Learn Chinese history man. Those farmers spread rice was from what is now southern China (read your own article you link) and their DNA proved they're different ethnicity (again read your own article).

Earliest paddy cultivation at Southeast Asia started at Mekong delta and around Tonlé Sap by the Mon and Khmer  people?

Sundaland was the southernmost tip of Asia continent?
Destroyed uninhabited after Toba super volcanic  eruption?

W&at happened to the Sunda race? Extinct?
Sunda race descendants are Austro-Asiatic people?

Based on Sunda Theory is the people originated from Pentas Sunda during the last Ice Age.

When Pentas Sunda sunk around 11000 years ago, the people there flee all over the place.

Later the people met with other people.

The one going north met the Inuit/Siberian.

The one going West met the Indians.

The one going South met the Papuan/Australia aborigines.

The one going East met the Islanders which is similar to Papuan.

From genetic and geographical point of view this make sense.

Of course other than the people in Pentas Sunda there are also traces of 'aborigines' that live in the inland which is similar to the Papuan.

Many of the people also have their own version of the Great Flood Legend depicting the sinking of the Pentas Sunda and people fleeing the continent.

http://journalarticle.ukm.my/13259/1/28422-89078-1-PB.pdf

Long arcticle for u to read.
There are a lot plant (flora) there but none paddy.

Lembah bujang is known as 1st civilization settlement/kingdom in south east asia. known as Kedah Tua kingdom. Happen around 2000 years ago.

Most civilization only learn about paddy/ rice/ congee after they trade with Chinese.

Ingat cerita org2 dulu makan ubi kayu, buah2, pucuk paku, ikan2 tu tipu ke...
Beras susah dapat la.

Ingat raja mesir/ firaun tu makan nasi arab ke? haha..
Yg dia tahu roti dari gandum je.

Ingat maharaja india 10ribu tahun dulu makan beras beriyani ke? haha..
Beriyani tu pun sekitar 500 tahun dulu dlm mughol empire.

Lembah bujang is over 2000 yrs old.

Chih Tu & gelanggi is new about 600 different la. 6th century.

Ige age happen 2.6million yrs ago. Human also not exist.

Nak kelentong tu, logik la sikit.

The Chi Tu kingdom is believed to have existed as early as 100 BC to the 6th century AD.[1] The royal family's name was Chu-dan (which means Gautama Buddha) and the king was Li-fo-duo-se.[2] According to Chinese records, Chi Tu was built by kit mow (Mon-Khmer) peoples who sailed from the coast of Funan (southern Indochina). Centuries later, the local inhabitants, replaced Funan peoples. "... Chi Tu is a derivation nation of Funan, located in within the southern sea, sailing hundred days to reach, the majority terrain was red, thus named Red Earth Kingdom (Chi means red, Tu means earth). East bordering Po-Lo-La, West bordering Po-Lo-So, South bordering Ho Lo Tan, thousands of square miles in land area.[3] The king has three wives and the kingdom embraced Buddhism ...".

The Last Glacial Period (LGP) occurred from the end of the Eemian to the end of the Younger Dryas, encompassing the period c. 115,000 – c. 11,700 years ago.