Whilst I didn’t see any mention of it in the SA Act, it would have been good practice for the Manager to ask for any motions from all owners to be put to the Meeting. Ours in NSW does so every year in plenty of time for the meeting.
The SA Act provides for notices of general meetings to go out at least 14 days prior to the meeting, so in your case it’s too late for anything to be added for a 10 June Meeting. I can only see it being appropriate for any extra motions to be considered at a later meeting with the requisite notice being given.
Regards
Dave