If you were to go around at this stage on the approach then you will see MAN TOGA SRS GA TRK (+Nav Armed on newer variants). The flight guidance section of the onside FMGC is commanding a vertical flight path with the conditions described in the FCOM. That is either the current speed at go-around engagement, or VAPP whichever is higher. It also goes on to say in the FCOM about the speed limitation with reference to VLS in two engine and one engine cases. What actually happens to the speed target I'm not sure if it will stay cyan or go magenta once go-around is engaged. Either way with SRS engaged I would like to think that the selected speed would have no influence any more!
Regarding the ATHR question this is in the FCOM under arming conditions. If you were to go-around (selecting levers to TOGA) the you are engaging the go-around mode. This will arm the A/THR displayed by a blue box around the font on the PFD. The ATHR will re-engage once they are placed in the operating range (CLB downwards).