Liberating Pre-Made Decks as a Mastery Reward

While it was nice to get 1000 runes for unlocking the "Beginner Deck" Pre-made deck for a lot of my Planeswalkers, the fact remains that I, and most veteran players of the game, will never, ever, ever use that deck. That means it's literally nothing other than UI button that I have to avoid hitting by accident when I am selecting a deck.

My suggestion is this: Make it possible to transform the pre-made deck slots into regular deck slots by gaining mastery. When a player goes from Bronze Tier in Card Mastery to Silver Tier, the "Beginner Deck" deck slot (when/if the player unlocks it by obtaining all the cards in it, as normal) becomes a regular deck slot that can be edited/altered/renamed/saved. Going from Silver Tier to Gold Tier would do the same for the "Expert Deck", when/if a player unlocks it, and moving from Gold Tier to Platinum Tier would unlock the Master Deck for regular deck-slot use, again, assuming a player has unlocked the deck by collecting all the necessary cards.

Pros:
1.) Players get some value from collecting all the cards in a pre-made deck, beyond a one-time rune payment; this makes it feel more rewarding to collect certain cards.
2.) For veteran players, these pre-made decks represent UI clutter; they are simply buttons we have to avoid pushing by accident. That's bad. This suggestion would eliminate this problem.
3.) For newer players, the pre-made decks would still exist for their use and guidance, while they're still playing at mastery tiers which are relatively appropriate for those decks and power levels; it would also provide a hint to them when they've reached a point where they should probably stop playing with these pre-made decks.
4.) It would address a lot of the player griping that people feel more crunched for deck slots now that we need to have both Standard and Legacy decks for regular events.
5.) Adds an additional benefit for going up Mastery tiers, which hopefully helps discourage people from staying below the appropriate mastery tier for their card collection.

Cons:
1.) Devalues the purchasable 200-crystal and 45000-rune deck slots. I have no idea how many players have been buying these (I haven't bought any) but this might be an issue.
2.) ???