Early believers contended that their respective bibles contained a witness to the primary revelation related to the origins of Judaism and Christianity. Canon formation takes a long time. While individuals may call for changes in the canon, religious communities play an essential role in the process. Scriptures which gain an authoritative status must prove useful over a long period of time. Church councils do not create canons but endorse those texts which proved to be useful for communities in practice.
Religious communities tend to be conservative about changes in their canons.
It takes individuals who have extraordinary authority in their religious communities to make such changes. The theology in the Bible is contextualised, which means that it is adapted and fitted to particular situations and contexts. The theology in any new Bible would also be contextualised or else it would be incomprehensible to humans. They will also have portions which will be objectionable to some people. Few would suggest that the Bible is the sole source of God's revelation.