Depends on what you mean by "akin". The core of Redux is just a few lines of code with a set of very opinionated conventions surrounding it, plus a bunch of utilities that people may or may not use. Angular's services serve a similar purpose to redux, but the approach is quite different. Mithril's idiomatic approach is similar to Redux in the sense that it's largely convention-based, but it doesn't actually require any specialized code. We could talk about non-idiomatic options, but from my observations, Redux is the most popular state management convention/library set for React and vuex is to Vue what Redux is to React.
In any case, were talking about a 2kb difference, so it's not like it makes that much of a difference.
Fetch is not required by any library, but a) realistically nobody uses the XHR API directly and b) projects typically do require XHR capabilities. If we're going to be removing things, note that Mithril and Angular are modular and can also be trimmed down if the comparison criteria involves removing things like XHR. Also, if "using the built-in XHR API" means re-inventing basic things like querystring parsing, then a library starts to look a lot more appealing again, and at that point, we're back to the point that Mithril's XHR utilities are smaller than most others that have comparable feature sets (e.g. Axios, superagent).