Sidwell & Blench (2011) discuss this proposal in more detail, and note that there is good evidence for a Khasi–Palaungic node, which could also possibly be closely related to Khmuic.
sˈɪdwɛl ænd blˈɛntʃ tˈuː θˈaʊzənd ɪlˈɛvən dɪskˈʌs ðɪs pɹəpˈoʊzəl ɪn mˈoːɹ diːtˈeɪl, ænd nˈoʊt ðæt ðɛɹ ɪz ɡˈʊd ˈɛvɪdəns fɚɹə kˈɑːsi pælˈɔːŋɡɪk nˈoʊd, wˌɪtʃ kʊd ˈɔːlsoʊ pˈɑːsᵻbli biː klˈoʊsli ɹᵻlˈeɪɾᵻd tə kˌeɪˈeɪtʃmjˈuːɪk.