I'm still waiting for someone to explain any legitimate use of kernel lockdown. To me, it just seems like a tool that makes it easier for bad guys to do tivoization.
To that end, the goal is in fact similar from a technical perspective to TiVoization! The only difference is that TiVoization is where the manufacturer of a device controls the device after it's been sold to a new owner, and lockdown is where the owner controls their own device. For the most part, this is a social constraint, not a technical one.
It shouldn't be surprising that the technical tools are similar between the two opposed social goals of user freedom and corporate control. The entire idea of free software licensing depends on the idea that software is copyrightable and its copyrights can be enforced in court. The free software movement demands access to source code to enable user freedom, but companies also demand access to source code for business continuity reasons using source code escrow services (if not for ongoing access - Microsoft licenses Windows source code to major customers, for instance). The GNU Project demands their contributors sign papers assigning copyright so that GNU is in a better legal position to enforce licenses, but so do proprietary software development shops, for exactly the same reason. They just are achieving different things.
But there is an important way in which this has technical implications: the owner of the device needs to be able to change. TiVo does not need to change who is the admin. That is why the lockdown work is harder. Remember that TiVoization actually happened without any of this work, and in fact happened so long ago that barely anyone remembers what a "TiVo" is.