Plyometrics and functional training are more aimed at performance outcomes. This can be sports performance, vocational performance, etc. There are numerous physiological adaptations involved in the recovery outcomes of these forms of exercise. Lean tissue adaptations are more profound in the the connective tissues (bones, ligaments, tendons, fascia). But if these are implemented correctly for the individual client, some increase in muscle tissue (density, volume, etc.) may occur. Or some degree of maintenance could be the outcome.(stasis vs. detraining).
More lean mass will be an adaptation for novice exercisers as compared to more experienced exercisers (if they have been training properly).
This may be a bit of a simplificaton of the subject, but it is as much information as I can give without turning this into a full blown physiology lesson.