Unlike Terry Pratchett's case, in which Twitter gave an author dignity on his way out, when it comes to brands and famous deaths it's often best just to keep quiet rather than try to join in the conversation. For example, with Prince's death yesterday:
These two are both awful examples of a brand trying to do soemthing heartfelt, but messing it up because they're trying to shoehorn their brand into the conversation - neither Cheerios nor 3M are immediately linkable in the minds of the audience to the tiny rockstar, and so should probably have stayed quiet on the mourning front.
I've got a lot more sympathy for this one - this is obviously a well-meaning Customer Service person, who's not really versed in the ways to approach something like this, and wanting to express their sadness as well as make their little Q&A feed seem a little more relevant.
And this just made me laugh. Perfectly on-brand for Pornhub, and a, erm, touching tribute.
The key here isn't humour - it's about knowing your audience, and about treating the death of a celebrity with the respect it requires. For most brands, that means staying the fuck away. No-one notices when a brand DOESN'T comment on something, but everyone will if it doesn't have the intended effect. Remember that a brand is selling things, and no-one wants to get advertising shoved in their face at a funeral. As for the PornHub one, well... No-one wants to think about death while accessing their site, so humour is really the best way for them to go. But odds are your brand isn't PornHub (if it is, please get in touch regarding any job opportunities).