The card is gorgeous, with deep purple and blue hues, intricate frame breaking, and it's a high rarity card that's highly playable as well
As well as the rarity symbol on the card, the rarity of a Lorcana card is also indicated by the colour of the icon
Ultimately, this is a placeholder solution so that more time can be spent on fingerprinting and identifying headless browsers (EG: via how they do font rendering) so that the challenge proof of work page doesn't need to be presented to users that are much more likely to be legitimate
As new cards come out, some cards usually get banned or edited to keep the flow of the game going
It was bound to happen sooner or later, but instead of just banning the card, the errata just makes you not want to use it at all
In Magic: The Gathering, for example, changes like this are reserved solely for digital-only formats on MTG Arena like Alchemy and Historic, where cards in players collections can easily be changed