From your link, it explains that they have to Switzerland:

"The developer of Session, an encrypted messaging app, has moved operations to Switzerland as ‘being in Australia just threatened our credibility as a privacy tool’."

What else in particular are you talking about?

With the phone number, I may have not remembered correctly for this particular software. If I could edit my comment, I would add a note.

But when going to the FAQ link I remembered how bad this piece of software was especially promoting cryptocurrency. I would never want a messenger to promote crypto, such a "Signal"

Edit: used different quote from the article