How are old people treated in the society of "Dusk?"
There is not a great deal of evidence in this story for how the society treats the old. We can infer some things from what Gortsby says about the old man early in the story, but we cannot know for sure that these things apply to all old people in this society or if they only apply to some of the old who are less lucky than others.
When Gortsby sees the old man, he imagines what the old man's life must be like. He sees the old man as someone whose family does not really care to have him around or someone who lives alone in a boarding house where no once cares about him at all. From this, we can infer that this is a society that does not care for or honor its old people. We can infer that the old are seen as a nuisance to be tolerated.
But you must be cautious about inferring too much. This is just one old man and he may be out in the park, uncared for, because of his personality. If his family doesn't care for him, maybe it's because he's annoying, not because he's old.
So you can infer that this is a society where the elderly are not honored, but you cannot be completely sure that this is an accurate inference.