They care enough that they don't like the novel writers going against it. Or so Christopher says.
A merchandising exec doesn't have the same powers as a creator of a TV series/movie. They go with Akira because that is what it has always went by. CBS isn't going to stop someone rolling out a multi-million dollar project from changing the name.
"The Cage"/"Where No Man..." uniforms are canon. No one is stopping Discovery from changing them.