The FCOM information is divided in different phases and the sentence about SRS needs to be read in relevant chapter. The sentence quoted is from TAKE OFF sub chapter and is with reference to only take off phase. For GO AROUND phase SRS engagement, it should be read in GO AROUND page which is quite clear and is as follows:
Setting at least one thrust lever to the TOGA detent engages both SRS/NAV modes, if:
‐ The flaps lever is at least in position 1, and
‐ The aircraft is in flight, or
‐ The aircraft has been on ground for less than 30 s (AP disengages and can be re-engaged 5 s after lift-off).