You should have been able to bring the item up in General Business at your AGM or to any Exec Committee meeting. The only items that cannot be determined are items that require a vote and the item was not in the agenda prior to the meeting for owners to consider.
The EC is required to maintain the building to current standards and need to seek approval for any changes that are seen as major. If there is a maintenance reason that means removal of the locks I see that as reasonable if required to perform the maintenance. A good strata manager and EC will notify owners and tenants however so there are no surprises.
Why don’t you try to get on the EC at the next AGM?