The two cards from Modern Horizons 2 were some of the most predicted targets to be banned in the format following the collapsing of the metagame to Affinity, Storm, and Dimir Faeries. Ian Duke stated in the update to the Banned & Restricted list that Storm had the highest win rate among top decks and earned by far the most 5-0 performances in Magic Online leagues. The deck being difficult to interact with was a key reasoning for the ban.
Affinity was targeted due to its high metagame share, not its win rate. The deck got many tools from Modern Horizons 2 — mainly the artifact lands and Sojourner’s Companion. WotC looked at other cards like Atog and Disciple of the Vault as potential options to ban, but settled on Sojourner’s Companion so that the archetype could live on in a weaker state.
The article pointed out that Galvanic Relay was also an option to ban from Storm, but it is being left in the format as a tool for other decks to use to generate value instead of winning the game on the spot like Chatterstorm. Storm lists featuring Galvanic Relay, Marauding Blight-Priest, and Weather the Storm have already put up 5-0 finishes in leagues before the update to the B&R list, so the pressure is on before the update goes live to see if the format can handle the new take on Storm.
WotC will continue to watch the format as the metagame shifts following these bans to see if any further action is required.
Read the original article from WotC.