The shutdown primarily affects users with older 2G devices, many of whom may be low-usage customers or those using the devices for specific purposes like emergency backups. While the majority of T-Mobile's subscribers are unlikely to experience disruptions due to the widespread adoption of 4G LTE and 5G, those still on legacy plans may face forced upgrades and potential price increases of up to $6 per line. The move also impacts international roaming customers who relied on 2G for voice calls.