Looking at how Apple works with other partners, it is more than likely to be ..
Considering that currently you are unable to watch anything on a Mac, I would expect Apple to see better Mac supprt from BT
You will not see an Apple BT box, but you will be able to view your BT TV subscription through your Apple tv Box.
Don't dismiss an 'AppleTV BTTV' box out of hand. There is such a device already in use in Switzerland - search Swiss mobile telco Salt for more details.
You can see the appeal from BT's perspective. It's got to be a lot less hassle for them (and a lot more attractive to customers) to dish out Apple TV boxes than continue to support/develop YouView ones.