Anyone who has objections to a Munich/Hillsborough banner is just being petty and mean spirited. The game would be being played close to the anniversary and it would be a very nice gensture. If there's cynicism behind the motivation of it, meh, I agree with Steve, it's better to be done, for whatever reason, than not, or indeed decried by people who didn't do it for the sake of one upmanship. (or even worse, belief that there's no place for respect within the rivalry)
I understand if some feel it's a cheap attempt to piggyback their way out of bother, but a) what does it matter as long as the message is positive and b) surely refusing to accept the gesture because of your tribal dislike of a rival club is a similar, if not sillier attitude?
You get the same from people who get worked up by celebrities doing charity for supposedly promotional or personal reasons. So what? They're doing it. Are you doing it? Are you raising awareness or even close to the amount of money they are? No, you're sitting at home in your pants finding ways to undervalue other peoples deeds. I'd rather people did good things for bad reasons than do nothing and bitch about other people's attempts.