GAC - I do agree with you that lack of confidence as a going concern does cast a pall over the stock. I am not so sure the actual statement does but the reasons for it being there do. Retail investors might not read the MD&A or if they do, are used to seeing that disclaimer and ignore it. Institutional investors probably look past it to the reasons that it is there and make their decisions on what they see. There might have been some stay away for that reason and prefer to wait for results to take some of that concern away. That might be why we mostly only have HL and KD interested.

I have not seen a definition of when it is necessary to add that disclaimer but it is more a decision of the entity to decide itself how they are going to report assets and whether they feel this needs to be added. If there are doubts, they are supposed to reveal them at that time. For this reason, I don't think there is any view that if they are solvent for one year, etc., that they don't need the disclaimer. RVX has an issue of no revenue and none expected for some time (maybe 2021 or longer). BoM results can have a distinct effect on that timeline and if not successful it can be extended substantially. These are the kind of things that they are responsible to disclose. Making a statement that they might not have the cash available to last the next 12 months is an upfront statement but not conclusive as to going concern stability past 12 months. I don't think there is a 12 month limit. Below is an IFRS exerpt regarding going concern filings. 

"IAS 1 requires management to make an assessment of an entity's ability to continue as a going concern. If management has significant concerns about the entity's ability to continue as a going concern, the uncertanties must be disclosed. If management concludes that the entity is not a going concern, the financial statements should not be prepared on a going concern basis, in which case IAS 1 requires a series of disclosures. [IAS 1.25] "

I think the middle sentence above would pertain to whether RVX can raise enough capital to continue, especially should BoM fail.

Going concern

The Conceptual Framework notes that financial statements are normally prepared assuming the entity is a going concern and will continue in operation for the foreseeable future. [Conceptual Framework, paragraph 4.1]

IAS 1 requires management to make an assessment of an entity's ability to continue as a going concern.  If management has significant concerns about the entity's ability to continue as a going concern, the uncertainties must be disclosed. If management concludes that the entity is not a going concern, the financial statements should not be prepared on a going concern basis, in which case IAS 1 requires a series of disclosures. [IAS 1.25]

Going concern

The Conceptual Framework notes that financial statements are normally prepared assuming the entity is a going concern and will continue in operation for the foreseeable future. [Conceptual Framework, paragraph 4.1]

IAS 1 requires management to make an assessment of an entity's ability to continue as a going concern.  If management has significant concerns about the entity's ability to continue as a going concern, the uncertainties must be disclosed. If management concludes that the entity is not a going concern, the financial statements should not be prepared on a going concern basis, in which case IAS 1 requires a series of disclosures. [IAS 1.25]