Staying true to the novels isn't necessary (it already diverts). This question is about whether Amazon will retain and produce the show until it ends, more or less around the same era and plot points of the novels. For context, the novel series spanned 14 books, not including the prequel(s), which aren't necessary to resolve this YES. From what little I can tell, the first season mostly stuck to the major points of the first novel, with some bits skipped and some later content added. The second season has started off with a blend of later novels.
If Prime drops the show, even if it's later picked up by someone else, this resolves NO. If they pick the show back up before someone else does, I'll endeavor to unresolve it. If the show "ends" in a way clearly discordant with the series, it also resolves NO.
Otherwise this resolves YES at the closure of the series.
The close date of this question is speculative and subject to change as necessary.