It still works in progress on my side.
However, in this case, all the books are hosted a rstudio connect server or other cloud service and the homepage just clean and filter links to present a nicely formatted listing to those books.
Considering bookdown books are static website, you can host them on any web server on your premise or in the cloud. RStudio Connect can help you with that. Then, you can build a homepage to link to your different book. This homepage can be a blogdown static website linking to all the different books.
If you prefer, I think It may be possible to host the different books as part of a blogdown website, using already rendered html or maybe using a custom build.R script to render each book. Unfortunaltely it is only theory as I haven't done it myself nor have any example.