/meta/00010000 is the subdirectory of /meta that is used for fake disc titles (installed titles using 00010000 as TIDHI). The only known title to have its WAD footer installed here is DataChk.wad, but this gets deleted along with the /meta/00010000 directory itself before the console leaves the factory.
The NandSDWorker seems to delete this directory together with /meta/00010001 every time the System Menu reloads; this may be what leads to DataChk.wad's title.met being deleted. DataChk itself also references this directory, possibly to delete it.
Creation
This directory is created by 122E as a result of the WAD library when creating /meta/00010000/30303032/title.met, but it is deleted by 0002 shortly after.
