I think it was a manufacturing issue more than marketing. The article says that SME was looking to expand its turntable output. it sound like they were faced with a choice of either building more factory capacity or cutting back on tonearm production to use that freed up capacity to increase TT production. Of course building equipping new factory space is very expensive and therefor risky) so they opted to reallocate the capacity they already had in house.
Of course the other factor that probably played into their decision is I the market for stand alone arms as far as I can see seems to be shrinking as most tables are now being sold with with their own proprietary arms. While in the past most high end TT manufactures did not make arms, leaving the user to pick out and buy the arm of his choice. This is no longer the case so I can see that faces with a quickly shrinking pool of even potential buyers SME decided to dedicate there manufacturing capacity to a product line that is growing (TTs) rather than one that is shrinking.
But I have to say, as good as my SME IV is, if I were to buy an new VPI table today, I would buy it with one of their 3D printed arms. It is just a whole lot easier to buy something that is pre mounted and was an integral part of the design and ultimate voicing of the table.