Answer: they have been removed from the stores in anticipation of the Proving Grounds event. This event will let players who do not yet have CAT at 7 stars nor the shards to do so obtain them. You get 20 shards per event and I believe it is refreshable for crystals to a certain point to earn more.
"Everything is proceeding as I have foreseen...mostly"
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Were the 5 other threads asking the same question not enough hints?