Textbundle is originally a folder contains .md + images and then compress to .textpack when exchanging. Sounds like .docx, right? However, .docx files can be edited directly by MS Word while .textpack files cannot be edited directly (correct me if I am wrong), we need to decompress it and edit text.markdown(the name is fixed) inside.
So, in my opinion that support importing from .textpack & exporting to .textpack is enough (just like Zettlr). Obsidian doesn’t need to support textbundle folders (means recognize a textbundle folder and show it as a note in file map). I don’t want to have many textbundle folder in my vault.