I doubt it’s coming unless parts are becoming unavailable. Also, as suggested above, there won’t be any additions that prevent Mki users loading up exactly the same projects. So if (and that’s a massive IF) it comes out, it’ll have tiny and largely under the hood tweaks such as slightly more processing power, a larger +drive, maybe the ability to switch inputs from line level to instrument level and so on. It won’t be revolutionary, it won’t suddenly allow stereo samples, there won’t be extra FX unless it’s also possible to add them to Mki units. It might have a different layout, such as some pads, buttons moved around, an extra knob for certain functions etc. Look at the AR, A4 and OT Mk2 changes for indications of what might happen.
But anyway, tl;dr, get an OT