For those unfamiliar with the ways of TCGs and erratas, it means that although the card has been printed and is in hands around the world, we read the card as its new, altered version, not as it was originally printed
I'm not sure which Lifegain decks would care much about Blood tokens, but considering how easy it is to make them with this 2-drop it may be worth jamming it even if you deck doesn't have much synergy with them
Per MaRo, new sets historically were added to Gatherer to coincide with the first prereleases, held in New Zealand (which would be Friday afternoon here in the States)
Illustrated by Naoki Saito, the full-art Lillie is considered one of the hardest of the three to find and ranks in position 13 for the most expensive Pokmon card ever sold, according to Vaulted Collection
Some may also feature foils or secret rares, inserted at specific ratios
At the very least the decks couldve had a lower price mark like those from some previous sets so the combo felt a bit more accessible