Certain part of a society are definitely different than other parts.
For instance, children are definitely a part of the society, and a very important part, but they differ from grown-ups in many regards. For one thing, they are dependent on their parents / guardians.
Other people, even totally grown up, may be considered so dependent on e.g. the government that they are not even allowed to vote due to the conflict of interest. E.g. US troops were not allowed to vote for most of the US history.
Were UBI enacted, I'm sure people who choose to live entirely off it, and people who choose to work (and thus provide the means for the UBI, among other things), will inevitably be seen differently, and you can't help it. Consider it when thinking about equality, integration of the society, etc.