Systems with microprocessors utilizing speculative execution and indirect branch prediction may allow unauthorized disclosure of information to an attacker with local user access via a side-channel analysis. This vulnerability so called Variant 2 (Spectre). Intel now work hard doing the remediaton of this flaw. We seen Intel new revision of MCU to replace the exisiting MCU. What is a MCU. A microcontroller (or MCU for microcontroller unit) is a small computer on a single integrated circuit. In modern terminology, it is similar to, but less sophisticated than, a system on a chip. My personal speculation is that vendor not only take this action. It also do a memory resigter in SGX module (refer to attached diagram). Intel SGX is a set of central processing unit (CPU) instruction codes from Intel that allows user-level code to allocate private regions of memory, called enclaves, that are protected from processes running at higher privilege levels. We heard that  another design flaw found on another CPU vendor. But comparing the responsibility point of view. Intel looks more responsive and responsibility.

For more details, please refer below url for reference.

https://support.microsoft.com/en-us/help/4090007/intel-microcode-updates