I understand your question, though I feel that there is a problem with it. Bear with me.
The Bible by definition is a very set series of books about the Christian faith. Even metaphorically, the word “bible” means something that remains dogmatic and unchangeable, even when it is obsolete. So in that sense, no, there could never be any change at all to the Bible.
Having said that, there have been a series of changes over the years, most often unwittingly, either when translating or even when interpreting the Bible. To add to the confusion, a word-of-mouth notion called “holy tradition” is added to what Christians consider to be their Faith (and of course different denominations of Christianity have developed their own versions over the years). It is this type of comfusion that allows common misconceptions, such as the notion of Mary Magdalene being a prostitute, something never mentioned anywhere in any religious or historical text.
Apart from all this, there could conceivably be a new book interpreting the central morality that belies the teachings of Jesus, the 1st c AD Jewish Rabbi mentioned in the New Testament. And this book could become the basis of yet another Christian sect. By definition a heresy, but sure, why not? It would probably be much closer to the truth than any of the current faiths.
And beyond all of the above, anyone who loves their neighbour and tries to be nice to people is bound to go to whatever Heaven there is. Even if they call themselves an atheist.