The Lumix GH5 will be the successor of four Micro Four Thirds cameras which have given us top video recording performance in a photography oriented camera body, at a reasonable price:
Timing
We have been waiting for a GH5 announcement since the Lumix GH4 was launched on February 7th, 2014. This is unusually long, more than two years.
However, keep in mind that there is a much lower turnover in the camera business now, since a few years ago. People buy much less digital cameras than around 4-5 years ago.
Looking at the announcement timings above, we can see that there are several cameras which are waiting for an upgrade: The Lumix GF8 is essentially the same as the Lumix GF7. So we should expect a less expensive entry camera soon.