Subreddits are reflective of the moderators and readers. There is no objectively higher criteria to determine whether a subreddit is or should be "free from bias", only that they should reflect the makeup their membership, which they do.

I think it absolutely does.

"unbiased" is, if hearing is given to a position, it is either not represented with favor or disfavor, or any expressions of favor and disfavor are combined in such quantity that there is no obvious position with respect to (un)favor.

"objective" is, if hearing is given to a position, it is discussed in terms of empirical data that persists regardless of subjective views or interpretations.

"balance" coverage is giving hearing to all positions, no matter how idiotic or inane. "balance" is giving nazis and jews equal airtime to argue their views on whether the holocaust is a good idea. "balance" is rapists and rape victims debating the merits of rape.