They could but I don't think it will be financially practical for an Aerospace company to set up a manufacturing line to just to manufacture 1 or 2 of the 225's.
It would also require quite a revamp, I guess, if anyone wanted to build it anew, those designs are quite dated (I mean, everything inside it)
The design is also very unique due to requirements that were put for it. Pretty much no one put similar equipment, and it's a wonder that it was "un-mothballed" at all and put itself on map again.
It was crucial for both commercial and humanitarian efforts, but no bean counter would approve building such design normally.