Well. This is in no real way threatening or concerning and doesn't really seem to provide any additional attack surface. But maybe I'm just getting old...
This service implements patching through what it calls “micropatches”, which are very small sets of CPU instructions injected into running code in memory without modifying – in this case – Microsoft’s own code. These micropatches are applied by briefly stopping the offending program, injecting the fix, and continuing the program – without having to close the program or reboot. Of course, they can be unapplied in the same, non-disruptive way. The 0patch service will provide patches for 0days that Microsoft hasn’t fixed yet, patches for issues Microsoft won’t fix, and sometimes patches for third party code.