They definitely seemed glossier, but not quite foiled out in the same way as regular cards
Over the course of facing off against different decks, the players would gain new cards to put in their decks and new abilities that modified how they played
It appears that they are explicit abilities, not inherent as in paper Magic, to simplify the rules implementation and type-changing effects in Arena
That said did you expect to see this card at number one on this list
For example, when working on Magic Origins , I made sure that Harbinger of the Tides was a "Merfolk!," not because of anything in Standard, but because it was a card I wanted to aim at a Merfolk deck in Modern and Legacy
Or as easy as one can in a world full of monsters, the undead, and whatnot