(Subtypes include but are absolutely not limited to: Plains, Equipment, Aura, Arcane, Jace, Curse, Urza's, Ulamog's, etc.) The ability that defines Subgoyf's power and toughness applies in all zones, not just the battlefield
This would be higher on the list if it were more impactful, but it really doesnt do much if it isnt an opening card you see
Last year they were April releases and previewed at the end of February
Problem is that even if youre at 40+ life, the moment you cast Felidar Sovereign, other players will try their best to attack you or kill your win condition, making this a little more balanced
Faeries were an iconic part of Eldraine and showed up in white, blue, and black, so it was a perfect fit
If tempo is important, you might include fewer tri lands or consider faster options