Official information from AXELOS and PeopleCert:

“we will be launching the higher levels of ITIL 4 in three phases:

A) 3 October 2019: Launch of ITIL 4 Managing Professional Transition Module and exam
The Managing Professional Transition module launch date has been prioritised to help you meet strong customer demand. For that reason, we will continue to review and incorporate feedback, as we launch the other Managing Professional modules.

B) November 2019: Launch of “ITIL 4 Specialist: Create, Deliver and Support” and “ITIL 4 Strategist: Direct, Plan and Improve” from ITIL 4 Managing Professional Modules

The definitive launch date will be provided w/c 5 August 2019.
C) Q1 2020: Launch of “ITIL 4 Specialist: Drive Stakeholder Value” and “ITIL 4 Specialist: High Velocity IT” from ITIL 4 Managing Professional Modules”