I am not convinced of this since the KOers can do it so easily at acceptable (matching with current reissues) levels of quality.
I say they just couldn't be assed. Yeah it cost money to recreate the mold but regardless of the cost amount, they probably just won't do it because there is a cost.
I am sure the people who made 'Bommander' Grimlock have less monetary resources to recreate a mold than Hasbro.