In the Wikipedia article "Dené–Yeniseian languages", it mentions about
His [Vajda's] conclusion was that, contrary to prevailing belief, such structures are often preserved intact with little change over several thousands of years, and as a result may actually be stronger evidence of a genetic connection than the lexical relationships that are traditionally sought. As a result, he agreed with the consensus belief that lexical evidence of a genetic relationship becomes virtually undetectable after about 8,000 to 10,000 years of linguistic separation, but suggested that certain sorts of complex morphology may remain stable beyond this time period.
I've been noticing some similarities between Austronesian and Salishan language families, like: 1) Pervasive Reduplication, 2) Weak noun/verb distinction, 3) Alienable/Inalienable Possession, 4) Numeral Classifiers, 5) VSO word order, 6) Attributive markers, etc.
Could such theory that complex morphology and syntax, to a limited degree, are preserved intact be used to link these two families?