Only the Tibetans in India occupied Tibet are Chinese. The other NE India people are similar to Burmese except they are Hindu, so they can join Burma.
I think China can support NE India indepence movement but the Burmese need to support it too. Chinese weapons can enter Assam through Burma.
NE people don't really identify them as anything but NAGA,MEITEI/MEETEI,MIZO -their native ethnicity.NE doesn't wish to join any other nation China or Burma. And north east state like Nagaland and Manipur actually have some disdain toward Burma due to territorial disputes. Kabaw valley of Burma belonged to Manipur but it was given away to burma without consent from Manipur king. Manipur and Burma have been butting their heads against each other for centuries .
North east is a christain province not hindu.
Even Manipur which many perceive as one of the Hindu state is actually sanamahi . The supreme deity of Manipuri meitei is not some hindu idol god but this-
^
Does that seem like your typical Hindu culture to you? dragon worship?
And the people of manipur scorn hindu festivities because it reminisces the occupiers from mainland . Somehow parts of Vaishnavism was impressed on Manipur through force by a king under influence of a bengalee Brahmin, but the people only took some parts of it like how japanese adopted parts of buddhism along with their shinto tradition.Now people are dropping hinduism altogether.
It would be an absurd notion to think NE states especially manipur would join Burma,their past adversary.It's like thinking vietnam would join china or Korea would join Japan. But NE have decent relationship with Burma.
NE people like manipuri/meetei have greatly distinguished themselves from Burmese in their history.
Even Major General J.Johnston the british envoy for manipur in 18th century ,clearly differentiated the Manipuri( meetei) and the Burmese,-"
Manipuris have stable and industrious qualities which the Burmese and the Shans donot possess.Manipuri(meetei) have much of the Japanese aptitude for learning.The men seem capable of learning anything and the women are famous weavers..they exceed even the ordinary Asiatic in reserve and sphinx-like characteristics,and the Manipuri race is an inscrutable set".