Unless we ditch BSEN3 and resurrect BS5423 I can't see it. It would put the price up somewhat and may put off some manufacturers unless they were likely to get a decent market share.
Of course unless a revived standard had a mandatory full colour coding clause it wouldn't mean the product would alter - after all even in the old BS5423 days we had unpainted stainless steel extinguishers and Amerex always used red bodies on their painted range. Wormald even had their extinguishers from TG in red with a colour code label prior to '97.
Of course if we did move back the industry could make a killing condemning stuff for being to the old standard and not mixing red and coloured extinguishers on premises in a reverse of what happened in '97.....