I've a slightly different perspective on reliably finding content from 'the rumor sites' ;-)
My feeling is that these sites want to cling on to visitors so tightly that you'll get not an ounce of real cooperation that might affect their [increasingly thin] bottom lines.
I set up [just as a few pages] the first dedicated rumour pages nearly 20 years ago - for a few years my [mostly Canon] rumours pages did phenomenally well (enough in ad revenue for my wife to give up a part-time job she hated and become marketing director for our main commercial photography business), but by 2010 everyone and their uncle was setting up XYZrumors dot com and I decided that it was time to wind down the pages. It became a chore, and my 'real' reviews and articles were becoming far more interesting to do...
I still keep them on our site partly for archiving and partly to keep up with what's happening in the industry, but updates are infrequent these days - as much as anything because 'real' rumours have become much more scarce, and most 'rumor sites' are just recycling scraps.
As to original content here - it's difficult to keep up the volume and quality needed for a good site, especially if it's to be at a suitable level of expertise and complexity.
I take note of Thom's comments here in that there needs to be a clear commitment to editorial independence, and that's not always easy. I've turned down 'ambassador' requests because it's taken years to build up a reputation for impartiality. Personally I could never afford to buy the stuff I test, but with clarity it's possible to test loan equipment and 'call a spade a spade' [we have a published review/advertising policy for example] - I try and stick to kit that I'll actually use in my work.
Having written stuff for ~20 years it's not easy to keep activity going!
Take note of those contributing here with that sort of experience, like Thom ;-)