The new section 8 notice is intended to be a permanent replacement because it contains pre-COVID notice periods.
The debt breathing space regulations allow a person to consult a debt advisor, and the debt advisor can start a breathing space. The starting of a breathing space means no action can be taken during the period of the breathing space, including serving a section 8 notice on rent arrears grounds or issuing proceedings (even if a section 8 has already been done).