pw_filter: link to the sound card is broken after plugging a headphone

Today I've noticed that my links from the last filter in the processing chain to the sound card are broken when I plug a headphone. I think this is something I can workaround by automatically recreating the link whenever a "default device changed" signal comes. But I am reporting this here because it does not seem right that PipeWire breaks the link because a headphone was plugged in the card.

I can see in my filters level meters that they are receiving data and processing frames. The last link to the sound card just breaks for some reason.