I was thinking the same as you, with Eurexpo probably playing a major role if the Olympic Village were located in the eastern part of the city:
a large arena for ice hockey or figure skating/short track,
several training ice rinks,
and it could even host curling and Hockey 2. (I don't think that will happen, though, because there would be nothing left for central Lyon.)
But after placing the "Confluence" Olympic Village on the map, I actually think that option works quite well too, with the Charlemagne ice rink right next door for training. They could probably also fit several additional training rinks, as well as a small competition arena, in the Halle Tony Garnier, which is also nearby.
In short, there are plenty of possibilities, but they will have to move quickly. And they would be better off discussing things internally before making contradictory public announcements...
We should have the final decision by the end of June!