Telepanel,

Warrants are extended all the time.  Check the Jr copper play, Copper Fox Metals (CUU) that I have been in for a decade.  Its a similar opportunity financially as RVX, ie HUGE underlying value but it is forever not monetized or commercialized due to management incompetence. 

CUU has been perenially extending all their warrants for years.  My understanding is that they are doing it for two reasons:  primarily as an acknowledgement (concession) that management has miserably failed to monetize a kings' ransom in a reasonable time frame, and secondarily so as to keep a potential source of future financing alive.   

As an aside, many of the warrants have advanced/accelerated expiry dates once the SP hits certain levels of 'in the money' prices.  So when the warrant becomes comfortably 'in the money' it forces the warrant holders to convert to shares (or let expire) and in doing so directly funds the company's operations.  Incidentally, those SP levels just got reached this week so the company, unless an anticipated buyout is announced or the accelerated expiry claused waived (they've done that too when they didn't need the money), will be getting a flood of money from exercising warrant holders. 

All to say that tons can be done to extend or modify a warrant's terms.