Canon USA now has firmware update version 1.1.1 available for download. This update is for the 7D Mark II. Here’s the LINK.
I don’t know how or why, but after some updates this last couple of days, I can now view actual thumbnails of my 7D2 raw files in windows explorer on Windows 10. I’m not sure if it was an adobe update (which iirc was a week or two ago) or this recent round of Win10 updates. Having been on mini vacay kinda fuzzed up my memory.
So, if you still can’t see your Canon 7D2 raw file thumbnails in windows explorer check if you’re up to date on your software (Adobe and Windows).