TVB's 1981 adaptation of DGSD notoriously deviated wildly from the novel towards the end of the story, but what was also very different in the adaptation is which characters died. The adaptation killed off many more characters than the original novel did, though there were a few instances where the reverse happened (e.g. characters who survived in the series died in the novel).
DGSD characters who died in the novel, but survived in the DGSD '81 adaptation:
Prince Deun Jing Tsun
Pau But Tung (wasn't seen again after the Beggar's Union meeting at Apricot Forest, but nothing was mentioned about his dying).
DGSD characters who survived in the novel, but died in the DGSD '81 adaptation:
Janitor Monk
Siu Yeun San
Mo Yung Bok
Mo Yung F'uk
Deun Yin Hing
Muk Yeun Ching
Boss Wu of the 36 Caves and 72 Islands
One of the four swordswomen of the Vulture Palace