Back in the day, the 5DII users were bitching "all day" that the camera had an amazing sensor, but the rest of the camera was a budget parts bin raid with an AF system from the dark ages. fine for the centre point and recompose...but forget any Servo tracking. Where as the 7D came along with a truely budget sensor (in comparision) but the rest of the camera felt more like what the future 5D series would offer. The sensor had relatively poor DR and iso noise. The 7D's AF system was a lot better than most realised, although limited to 19 points, it was suprisingly good at tracking. It also paved the foundation tech for the 1Dx / 5DIII's 61 point AF system. The 7D's AF system was vastly different to that of the 1D series of the day...however the 1Dx then looked very much like an evolution of the 7D's AF system. I saw the 20D as the furture direction of Canon DSLR's, the 40D was amazing with it's Live View implementation (where I predicted a mirrorless future) and the 7D with it's ground breaking AF system which was a prototype for the future of canon's AF systems going forwards.
I didn't see similar interesting tech in the 7DII....it just seemed to be another stale warm over that canon seems to drop on us every now and then. So I've never bothered with a 1.6x crop camera since. The 7D series was too much of an image quality compromise for me.
The R7 is a really cheap camera at the moment. It's reasonable to suggest and the R7mkII is likely to be the same camera with the R5II AF updates, dual SD cards and a common 5Dii/6Dii user nterface / button array. But with a heaftier bump in price with the original R7 being sold as it's cheaper model.
For me the purchase descision of the R7ii is really dependant on the image quality and bang for buck over my existing cameras. If a R5ii is a better option (with it's really useful 18mp 1.6x crop mode) vs a R6iii and a R7ii. My current R6ii is staying because it's such a sweet camera and might prove to have a few 1st curtain shutter / mechanical shutter, iso / image quality advantages vs the ES cranked speed demon the R6iii is likely to be.
I think if it was starting again on canon and wanted a dedicated camera for wildlife it would be a serious consideration. However, both the R5ii and current R6ii offer a lot already.