Alex,
it seems like you're asking 2 or 3 different questions here, so I'll do my best to untie the knot, and we can proceed from there if I've missed a/the point.
The B&O remote will send whatever command is appropriate for the button(s) you've mashed. The issue is that there are at least 3 languages or command sets which might be sent; Audio, Video, and Link. The B&O Masters (audio and video), and certain Link devices, can be instructed as to which language(s) they are expected to respond to. So if you have a B&O TV set for 'Video only' (Opt. 1) it will ignore any Audio commands; but even if it is set to respond to both Audio & Video (Opt. 2), if there is no Audio device available, the command will result in no action/response because the TV will not be able to pass the command along. If as you suggest, you have pressed a Video button on the remote in a room in which there is only an Audio Master (in Opt. 1), then, yes, it will ignore the remote untill an Audio command is sent again.
So far, all of the communication we're talking about here will happen via MasterLink, Master Control Link, or DataLink. Your question mentions PowerLink, which seems oddly out of place...PL is a connection between a source and BeoLab speakers; it carries the audio feed and in some cases, the data needed to drive a display on the speaker...PL has essentially nothing to do with command and control of Masters.
We kid because we love.
Bang & Olufsen Tysons Galleria
McLean, VA USA