Tethering support usually lags one or more versions behind when raw files are supported, and Adobe doesn’t preannounce support, usually, so anyone knows what the internal schedule might be cannot post on a public forum, anyway.
The 7D Mark II has only recently been supported for raws and it may be a few versions more before tethering works. Since we’re already up to LR 5.7 of the LR 5 series, it’s possible that the version of LR to first support tethering would be LR 6—assuming there is a LR 6.
In the mean time you may find it works to tether using the EOS Utility and then set up LR with an Auto Import folder pointing to where the EOS Utility is putting the photos.