No, there are two main reasons.
* The dl should be as lean as possible
* Bundles will complicate legal issues
Both are important. We have a homepage, where you can find links to the add-ons that any one, find interesting for lmms.
https://lmms.io/wiki/index.php?title=Useful_resources
On top of that, there is a sharing-portal.
https://lmms.io/lsp/
If you have any specific wishes for soundfonts you think should be on the list, you are most welcome to either signup, and add them, or just list them here, and they will be added later.