Hi @Jyndevad and welcome.
Short answer: Yes.
Long Answer:
Well, I am afraid that is just not like Homey voice assistant integration works. That does not mean that what you want is impossible though. You can define voice command triggeres in various ways which would enable you to play your preset. It just does not work out of the box as you imagined.
For example, you can define a flow which will start preset 1 of your soundtouch device. This flow can then be made a so called favorite which will enable you to trigger that flow with your voice by its name.
Also you could add a virtual device which would do and work almost the same.
