To end the discussion, culminating here, here's a sketch of the "do a little less" approach. It's typical for a solution using inventive principles that it's no longer needed to focus on Latex (in this case), use other available resources, and shift attention to other things, not needed before. AND ... it opens up new opportunities, which were not available before. This one became more procedural this way than latexian.
In its simples form it continuously overwrites the drawing of the week (new title) AND the book, and delegates backup or versioning to a dedicated tool, like git.
For this example, to illustrate the concept, I assume a kind of mix:
- ONE file from a graphic tool ONLY (Inkscape, Illustrator, ArtWhatever), weekly stored as
title.png, which never changes
- one folder per week for the weekly book
So let's go.
Organizing files and folders

This is something you have to decide on. This structure assumes:
/graphic will hold the title.png
- which is overwritten weekly, i.e. lost as an individual file
- (use git etc. to compensate for this loss)
For /book-n I assume, because the examples OP so likes it, to:
- create a new one every week
- copy
/book-(n-1), rename it into /book-n
- start editing its
/book-n/book.tex
So inside it will look like this:

Accessing the weekly title
From inside folder /book-n it's always clear where to find the latest title-image:
../graphic (/title.png)
- no matter how complicated you distribute everything accross your computer (then the path will be a bit more complicated, too)
Graphics for the title page
I'm not claiming to be an artist. I used a painting -program, to create 2 drawings, exporting them to title.png week after week ...
Book-1, the first week
Just edit and compile:

\documentclass{book}
\usepackage{graphicx}
\usepackage{lipsum}
\begin{document}
% ~~~ this part you design only once ~~~~~~~~~~~~
\begin{titlepage}
\includegraphics[width=\textwidth]{../graphic/title}% fixed location
\vspace{2cm}
\begin{center}
\Huge{
by
\vspace{\stretch{2}}
Super-Author
\vspace{\stretch{1}}
}
\end{center}
\end{titlepage}
% ~~~ here is your next version ~~~~~~~~~~~~~~~~~
\chapter{And so it begins}
\lipsum[1-2]
\end{document}
Book-2, the nextweek
Just edit and compile:

\documentclass{book}
\usepackage{graphicx}
\usepackage{lipsum}
\begin{document}
% ~~~ this part you design only once ~~~~~~~~~~~~
\begin{titlepage}
\includegraphics[width=\textwidth]{../graphic/title}% fixed location
\vspace{2cm}
\begin{center}
\Huge{
by
\vspace{\stretch{2}}
Super-Author
\vspace{\stretch{1}}
}
\end{center}
\end{titlepage}
% ~~~ here is your next version ~~~~~~~~~~~~~~~~~
\chapter{What happened next}
\lipsum[3,7]
\end{document}
Automation-aspect
In fact, there is hardly or nothing to automate: the problem is gone, depending on how you organize it.
In this example, one new book-folder-per-week, it remains kind of tedious, as at least you need to copy and rename the book-folder. (Is it worth to automate that by a (shell-)script? May be not ... but you can do it.)
The title-drawing will be created new and overwritten anyway, so that's no extra work.
So, to get rid of the copy effort ... use one book-folder only AND a backup/versioning tool like git. I.e.:
- work with a fixed structure
- save, retrieve, branch etc. intermediate versions to your needs
P.S.: Just to be complete, this is a generic feature of so-called inventive solutions. They provide:
- automation (in this case) AND no-automation (its opposite)
which translates here as:
- no-automation: it's gone, because the concept or approach changed
- automation: the effect of prior needed automation is provided.
Do you still need a script?
No, you replaced it either by nothing or the git-console (preferred) or the git-GUI ... like in this example from the net:

Any new opportunities on this path?
If you haven't used it before, using git you can:
- save, save, save
- name (intermediate) versions
- retrieve, go back in time
- branch, i.e. try a different route with your content
- return to your previous branch/version if it doesn't work out nicely
- etc.
If you use the ONE graphic ONE book-folder only approach AND overwrite it day by day, you've earned a clean evolving workspace on your computer.
And so on.
git, but it has some featuresgitdoesn't. I like having the versioning info in the file and there are LaTeX packages which let you typeset it in drafts, for example. – cfr Oct 06 '23 at 23:41