The big question is will these new workouts use sensors in a different way for each workout?
If not I see no reason to be excited about adding new workouts or workout icons.
The "Other" workout type can be selected when you have completed your workout, i.e. HIIT training etc.
They are not new workout's as such, they are just sub-categories of the "Other Workout" type.
The new workout type's that others are discussing here is in relation to the images that were leaked recently, they are unrelated to what you are referring to.
How to name your "Other" workout:
Save a custom workout. Start a workout with the type Other. When you’re done, swipe right, then tap End. Scroll to the bottom of your workout summary, tap Name Workout, tap the type of workout, then tap Save.