Re: Confirmed: Kakashi is either dead or....
1. The Kamui dimension is separate... as noted by Hinata and sensors, his trace is completely vanished meaning no link exists between dimesnions.
This means that when giving out his chakra, Kakashi plausibly never received any for the link.
2. We haven't seen him on the battlefield, and his presence is being hidden for a more dramatic revelation.
Still... If you are right, I'd say at the very least it means the FTG cannot escape. For if Kakashi got another chakra boost, he can now escape Kamui. However, with his current injury of his side/shoulder wound, he'd need to teleport perfectly, or he'll get in the way.