Security patch SA-18:03 removed from 11.2 - why?

[Peter]

Release/update 11.1-p8 introduced so-called "mitigation for speculative 
execution vulnerabilities".

In RElease 11.2 these "mitigation" have been removed. What is the reason 
for the removal, and specifically why is Security advisory 18:03 still 
mentioned in the release notes?

Behaviour with 11.1-p8:

# sysctl hw.ibrs_disable
hw.ibrs_disable: 0
# sysctl hw.ibrs_active
hw.ibrs_active: 1

Behaviour with 11.2 w/ same CPU + microcode:

# sysctl hw.ibrs_disable
hw.ibrs_disable: 0
# sysctl hw.ibrs_active
hw.ibrs_active: 0