Deck structure doesn't change after importing new version with a different structure

I’m facing a little difficulty in implementing an update to my shared deck on AnkiWeb.

The older version (v0.9.3) of my deck has this structure, and subtopics are classified via tags :

r/Anki - Deck structure doesn't change after importing new version with a different structure
v0.9.3 (in shared deck profile)

The update I wish to implement (v1.0.0) has this structure, wherein I’ve ditched my tag system and organised it via subdecks. (I know it’s ugly and inefficient; there’s a long story as to why, but it had to be done)

r/Anki - Deck structure doesn't change after importing new version with a different structure
v1.0.0 (in demo profile)

I made a test profile in Anki desktop to see if the update would properly work for existing users. Imported v0.9.3, and then imported v1.0.0 after that; the structure still doesn’t change after the update. (the 80 cards you’re seeing which follow the new structure consist of new cards; the old cards don’t automatically shift to other decks)

r/Anki - Deck structure doesn't change after importing new version with a different structure
v1.0.0 (imported in shared deck profile)

Is there any way to make this new subdeck system update work, without making a new AnkiWeb + GitHub listing? How do I make this update work for old users?