All Standard-legal cards released from Guild of Ravnica onwards are legal in Historic, and there are some sets like Lord of the Rings: Tales of Middle-earth , Modern Horizons 3 , or several sets bonus sheets that, although they werent legal in Standard, were greenlit in Historic
This isn't a first for a Secret Lair or anything, but I asked Heggen if that sort of thing is something they actively think about when choosing the cards for each new drop and while he didn't address the prices of cards specifically, he did say picking the right ones is more of an art than a science
For each card of the chosen color exiled this way, create a 1/1 blue and black Faerie Rogue creature token with flying. Its incredibly against mono-colored decks, so thats well worth considering
Meanwhile Simba is one of the cheaper cards, at only two Ink to play