Guide 7 restricts a mining company in the exploratory phase from stating reserves at all
That is incorrect. Industry Guide 7 does nothing of the sort.
To claim reserves, a Company must have a full (bankable) feasibility study which not only proves the existence of minable minerals on the property, it must also prove the minerals can be economically and legally extracted. A feasibility study is always prepared and completed at the exploration stage for a company not already in production.
The next stage above exploration stage is development stage. To qualify as development stage, a Company must actually have all required permits in hand and be developing the property (i.e., building a mine). A Company can have a feasibility study and reserves but remain in the exploration stage for years and years. It takes a long time to obtain permits and the financing required to begin development and during that period the Company is still classified as an exploration stage company.