Auto Smush for New Image Sizes?

Hello. I just read this one right here and need some clarification:

In there you say "It compresses all the resizes, even if you make one later", I'm still unclear in this part.

Say, my current theme use 4 image sizes, then 1 original + 4 resizes will be smushed, totalling 5 smushes.

Does it mean that if I change to a new theme which use 6 image sizes, then wpsmush will resize the 2 new sizes automatically? (totalling 5 old smushes + 2 new smushes)