Is there any possibility of Sun Networks launching any Hindi/Odia/Assamese channel(s)?
I don't have hopes with Sony launching channels, cause their mainstream SONY ET is itself suffering from low TRP. Also, Sony Aath may not ever air originals, Sony Marathi also has low viewership.
Regarding Viacom 18, Colors Telugu is launched on Voot with dubbed Telugu shows (I don't know if ever they would get a channel too, as it may replace/clash ETV Telugu). Colors Malayalam is a possibility though, but Colors needs to regain it's power in Bangla, Tamil, Odia and Gujarati markets and maintain dominance in Marathi and Kannada markets.
Zee has a wide range of channels (TV, Bangla, Big Ganga, Marathi, Odia, Tamil, Telugu, Kannada, Keralam, Punjabi). Only ones left are Assamese and Gujarati (Gujarati was closed in 2009, so may never reopen).
Star's only left ones are Odia (maybe via Tarang TV) and Assamese (if Rang TV is possible). It will never venture into Bhojpuri, Punjabi and Gujarati market.