Changing to fibre telephone if you only use the Superb as a modem?

I already had a perfectly good (and secure) router installed in my home when I moved to virgimedia. Rather than use the supplied superhub as a router, I used the UI to switch it into modem mode and connected my existing router to it It's been working flawlessly for many years and I have no intention of changing this.

Today, we've been given advanced warning that we are being migrated to telephone over fibre. The instructions say that our DECT base station will have to be connected to the Superhub. Does anybody know if this will work if the Superhub is merely a modem?