Looking at this change https://github.com/wikimedia/mediawiki-extensions-Math/commit/d8822169ab5a959b5b4fa2642616ef5301fe1b63 it seems it is only adding support for mathoid without restbase if you install mathoid locally.

If your a a large wiki who is across several mw servers you won't be able to use the cli or can you?

But if you have private wiki's the support to directly use mathoid would be a benefit as currently restbase does not support private wikis.