The invention of the new Welcome Booster is a clear response to a WotC survey where they discovered that only 4.7% of Engaged Players started with a Welcome Deck. As the number of Engaged Players is a key metric to qualify for WPN Premium status (see "WotC Cuts Requirements for WPN Premium Status by One-Quarter to One-Third"), WotC decided to help retailers out a little by doing away with Welcome Deck and replacing it with a new Welcome Booster.
Each Welcome Booster contains 10 cards, which includes an assortment of powerful rares and a Planeswalker card. The cards are selected from all five colors as well as different formats. In certain regions, the Welcome Boosters include a code for Magic Arena which can be redeemed for an introductory deck. The design team hopes that these new starting boosters will showcase what players like about Magic, and draw new players into the game in a post-COVID 19 world.'Magic Arena Starter Kit'"). The Arena Starter Kits are meant to "serve as demo decks that players can purchase", which is an interesting use of this product that will likely have trouble competing for customer attention in the middle WotC's cavalcade of summer releases (see "Super Summerdrop Announced for 'Magic: The Gathering's' 'Secret Lair'").