IMO, these latest developments are not totally unexpected given...

IMO, these latest developments are not totally unexpected given Rio has previously indicated they wished to construct their own coal-fired power station. Where Elixir was always going to fit in, was as an additional supplier to supplement their Oyu Tolgoi project's power needs.

As the article indicates, although a government-built power station would help to reduce Rio's near term spend on their Oyu Tolgoi expansion, this may become an issue long-term given the government's potential "control" over the project:

For this reason, I believe Rio may still be willing to partner with Elixir in the right circumstances. This may be after Elixir confirms a commercial gas resource, or perhaps even now, given the latest developments which potentially threatens their control over the project...