These are exclusive, limited availability collections of cards with alternate art or styles that are only sometimes playable in competitive formats
The best way to remember this is to note that every card in collector boosters has some form of premium treatment, either being foil, showcase, or extended border, whereas cards from The List show up as printed in their original set, albeit with a planeswalker symbol on the bottom left
TEMPO IN COMMANDER Tempo in Commander is another story
Like most Pokmon cards, the value of Piplup depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Majestic Dawn)
Sure, you now lose even more ground to Karn, the Great Creator, but Stony Silence has been the bane of that deck for years
I know South Korea would reassign the indices if cancellations occur but havent seen Japan doing the same, and unfortunately Japan was also known to keep some of them missing forever as weve seen in BW-Ps