IoT devices and applications to only use TLS 1.2 for communication with IoT Hub and DSP

To provide best-in-class encryption, IoT Hub and Device Provisioning Service are moving to Transport Layer Security (TLS) 1.2 as the encryption mechanism of choice for IoT devices. As such, legacy support for TLS 1.0 and TLS 1.1 as well as several legacy ciphers will be deprecated in July 1st, 2020.
Source: Azure Roadmap