surprising lack of interest in G5 review

I found this interesting too. People end up debating their perceived merits and lack thereof of the G5.

In fact, there is a perfectly straightforward explanation to the observation in your OP. People, presumably those who want/need to see a review, pine for one when it had not been available. When one becomes available, they all rush to read it and for most of them, their desire has been satisfied.

It will then be a different set of people (with some overlap perhaps) who have formed views about the G5 (mostly no overlap as if you already have strong views, why bother complaining the lack of a review), who are attracted to G5-titled threads and start debating their own views, which is exactly what's happening here.