There's been talk of Ninja Theory's next title being at E3 with a release as soon as Early 2020. There was also this 4chan rumor recently on the subject.
While all rumors should be taken with a grain of salt. This current write up doesn't seem like it would be out of line for NT (Though even I don't believe all of it like the 6 year dev time). I recall other such rumors seemed to indicate that it would indeed be a game with a MP focus. Which will likely heavily rely on the art design and gameplay to carry its concept (Since a MP focused title I can't imagine having such a heavy story focus like Senua).
Id expect that NT making a SP focused game like Senua or Enslaved with a bigger budget (If they decide to do those again) would be something they save for the next Xbox after all.
While all rumors should be taken with a grain of salt. This current write up doesn't seem like it would be out of line for NT (Though even I don't believe all of it like the 6 year dev time). I recall other such rumors seemed to indicate that it would indeed be a game with a MP focus. Which will likely heavily rely on the art design and gameplay to carry its concept (Since a MP focused title I can't imagine having such a heavy story focus like Senua).
Id expect that NT making a SP focused game like Senua or Enslaved with a bigger budget (If they decide to do those again) would be something they save for the next Xbox after all.