A trans woman has some photos of her and her partner on her profile. Her partner then murders her, is arrested and sent to prison. Her profile is memorialised. Her family gets access to her account from Facebook and replaces all of her photos with photos of her before her transition.
Facebook has no way of knowing the motives of people so they don't try to.
The third option Facebook takes is to control it themselves. That's just not right.
Facebook could very well deal with a list of images to remove and the reason for it. In this case, the reason is cristal clear.
If someone else wants to "memorialize" them, they should just do so on their own active account, using whatever content they deem fit.
You don't need a Facebook page for people to know you existed.
About 2 women a week are killed by current or former partners in the UK.