Funerals are for the living and not the dead. You can write you own obit, but nothing forces anyone to use it. If you put it in your will, your funeral is over before the will gets attention and/or through probate. I agree that I read those kind of obits as reflecting on the author and not anybody they are dissing.
As for end-of-life relationships, they are to be enjoyed by the two involved and have nothing to do with anybody else. The way I see it, no 'end of life' girlfriend/boyfriend should take any offense if they are not acknowledged, or the family does not think 'they are good enough'. Ther '7-year itch' is not just a movie or a saying... if a person's lifetime of relationships reflects most if not all not surviving the 7-year itch, then it means their 'picker' focused on the 'right one for now' and not on the long-term projection. If a man in his 60s+ is not courting the person whom is seen as dependable to be changing his diapers and/or colonoscopy bag, administering his daily hygienic requirements, running him to constant doctors, administering daily nursing aid and recognizing their sex life will most likely be when she gets a booby tweak as she walks by him and a goose when she bends over to put on his socks and shoes then she is not 'the keeper'. The man's family is most likely already aware.