WIP: TST: pass random names in tm.makeDateIndex
@WillAyd nearly all of the remaining test failures locally are in the json tests.  can you take a look and suggest whether we just need to pass `check_names=False`

I expect if we do something like this we won't want to actually randomize; that part I guess is a proof of concept for now.
Just at a brief glance not all of the JSON formats preserve index names. Split is a particular example which came up in #17393 Just curious: what was the motivation for adding this? > Just curious: what was the motivation for adding this?

We are using these functions for fixtures that are aimed at trying to cover a wide swath of possible index objects, but are missing large parts of that space. closing to clear the queue, will keep trimming away at these locally