I can't see why it couldn't work. The 3-pin IR receiver modules (as the 38 kHz one
as described over there) output the demodulated base band bit stream,
and after that time B&O remotes aren't any different from others.
If the software just compares the input to a previously trained pulse pattern without trying to decode it somehow, it should be fine. Beware though that some B&O commands can be quite long and the
software of this receiver might not be prepared for those.
You
will of course need to fit it with a 455 kHz receiver module, as you
say. The difficult thing here is that Vishay has discontinued the
TSOP7000 IC, and I don't know of any replacements. If you manage to find
them somewhere, keep in mind that their pinout is different from the
lower frequency parts, although they look the same!
You could probably also use a B&O "hockey puck" IR transceiver as the receiver.