Like most Magic: The Gathering cards, the value of Thassa's Oracle depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Mystery Booster 2)
ramping and cheating spells into play is very strong, and in many ways the fact that Golos is the perfect Mono-white Commander says it all
Lorehold Charm, meanwhile, can force opponents to sacrifice creatures, or return its caster's creatures or artifacts from the graveyard, showing how Lorehold students have an affinity for artifacts and unearthing the past, In a YouTube short discussing the new charms Gavin Verhey, one of magic's lead designers, talks about the team's design goals with them
That would be fun, right
Either it's a subtle clue about the true identity of the final set of the year, or someone on the MTG Arena team is messing with us