The OM-1 versus GH6 battle is an interesting one that is good for the consumer. The GH6 obviously has the edge in video features, but if the auto-focus proves better on the OM1, and you prefer the lighter body of the OM1, then for some use cases, the OM1 may fit the bill better.
Here is the first longer form video shot on the OM-1 that we have seen: