>>908for simple concepts like "going out" or "come" yeah, but for abstract stuff like "happy" "friends" "love you" and so on I doubt they make a meaningful distinction. Aside from the voice the owner praises them all the same and the dogs would get similar results if they were mashing those buttons randomly, the feedback doesn't seem obvious enough.
Temporal concepts like "soon" and "later" are pretty suspect as well because their definition isn't even clear between humans. They're interesting to study though, I don't think we know to what extent dogs plan for the future so far.