All Secret Lair MTGA Codes fall in the category of cosmetic codes
In that video the second (and presumably final) Planeswalker card of the set was revealed: a new depiction of the antagonistic Tezzeret, originally from the Esper shard of Alara
There probably are allied color archetypes, but this set is dense and a cursory examination seems an even poorer substitute for playtesting than normal
Tegwyll, Duke of Splendor not only provides a substantial buff to your Faerie Creatures, many of which are likely very small to begin with, but it also provides you with card advantage when your other Faeries die
yes, you want to lock the game as quickly as possible, but you also want the game to continue under that lock for as short a time as possible
Decks that combine together enemy MTG colors get none of that coherence or dedicated strategy - but they have the benefit that one color's strengths can cover the other's weaknesses