It was explained by Ryan Miller that these changes make it easier for different language cards

Advanced Search Sets Random Syntax Acid-Spewer Dragon Adult Gold Dragon Akoum Hellkite Akul the Unrepentant Alabaster Dragon Amareth, the Lustrous Ambitious Dragonborn Amethyst Dragon Ancestor Dragon Ancient Brass Dragon Ancient Bronze Dragon Ancient Copper Dragon Ancient Copper Dragon Ancient Gold Dragon Ancient Hellkite Ancient Silver Dragon Ao, the Dawn Sky Arashin Sovereign Arcades Sabboth Arcades, the Strategist Arcbound Whelp Archive Dragon Archwing Dragon Armament Dragon Artificer's Dragon Ashmouth Dragon Astral Dragon Atarka, World Render Atsushi, the Blazing Sky Avaricious Dragon Avenging Hunter Backdraft Hellkite Bahamut, Warden of Light Balefire Dragon Beledros Witherbloom Belltoll Dragon Betor, Ancestor's Voice Betor, Kin to All Bhaal's Invoker Black Dragon Bladewing the Risen Bladewing, Deathless Tyrant Blast-Furnace Hellkite Bloomvine Regent Blue Dragon Bogardan Hellkite Boltwing Marauder Bone Devourer Bone Dragon Bonehoard Dracosaur Boneyard Scourge Boulderborn Dragon Brainstealer Dragon Brimstone Dragon Broodcaller Scourge Broodmate Dragon Broodmate Tyrant Caldera Pyremaw Canopy Dragon Canopy Gargantuan Capricious Hellraiser Catacomb Dragon Cavern-Hoard Dragon Chaos Dragon Chardalyn Dragon Chiss-Goria, Forge Tyrant Chromium Chromium, the Mutable Clarion Conqueror Clockwork Dragon Cloud Dragon Colossal Grave-Reaver

Sapphire also has a lot of access to Disney Lorcanas Ward mechanic meaning they cant be chosen as a target for action cards which increases your characters survivability
There's no guarantee that you'll have a second target, but in a color combination that's often starved for cards, getting as much value out of each spell is paramount
I know you'll have a blast
Number Four: Double Vision Of all the cards on this M21 list, none of them require fewer explanation as to their scalability and general usefulness in a Commander game than Double Vision