We already kickoff the early game at 6pm on a Friday for Foxtel viewing. But yes, the later the kickoff, the better the crowds and TV audiences. However, I also doubt the NRL would bring in a kickoff later than 8:30 for the second game.
It all depends on bidding broadcasters and expansion team locations. Channel 10 could easily run coverage from 6 to 11.
Channel 9 would only cut their news if they had full exclusivity to those two matches, because the viewer loss at the moment to Foxtel is too great to justify ending the news half an hour early and dropping ACA. But with 2 exclusive games, what they lose in News/ACA they make up for in exclusive national NRL viewership across a 4.5 hour block.
So if 9/Stan were the sole broadcasters, in southern states they could run their news as normal. But in NSW/QLD/ACT they could end the news at 6:30pm on a Friday then leap into NRL coverage to 11pm with 2 back to back games. If the second game started at 8:30pm and had a 15 or even 20 minute half time, it would like finish around 10:20pm. However, if the second game was in Perth, it could start later 9pm EST/7pm WA and run to around 10:50pm. Again - all depends on broadcasters and team locations.
Ideally though out of the 4 teams playing on a Friday, there'd be at least 1 Sydney team, at least 1 QLD team and a team from either Perth/Melbourne/Adelaide to ensure that at least 3 metro regions are targeted. If the early game is in New Zealand, obviously the 4th team would be Warriors or NZ2. The idea is to get audiences from all 3-4 areas watching across both games.