I have made a conjecture. This is the sequel to my previous post concerning the big green button that came alongside Soda Islands.
Is the move count limit of 15 or lower, and is the move count dependent on the level rating a test feature?
Background
It has been confirmed that the big green button for level selection is a test feature, per @claudia_calamar 's statement:
The recent changes in move count came just a few weeks after the introduction of the big green button.
Findings
The 15-move limit came entirely from forum posts. The consistency of the move limit and the similar pattern for Hard and higher-rated levels is greatly concerning. CCS's moves distribution still showed a skewed bell curve centred around 25 moves, with 14 as the low end and 41 on the high end.
Very little CCSS footage exists for players who played a level by clicking on the big green button that replaced the level cards. In fact, I could not find a single YouTube video of players playing under the new layout. This is a suspicious sign that players have decided to cease all progress on the game.
I have completed exactly zero levels under the second test. I have completed exactly one under the first Previous Levels test of April/May, and only for reviving Soda Islands.
Moreover, I found out the game has become entirely live-service no earlier than the first test on previous levels (which has been rejected) to ensure that levels have to be played under the newest redesign, with only the first 100 levels or the next dozen or so levels accessible when the player is completely offline.
Therefore, I conjecture the 15-move limit is a double whammy of a test on top of the big green button. Please do not click the big green button.