As I have repeated before, it is hard to read CBS' relative lack of investment in Enterprise as indicative of what the studio would do for Star Trek: Deep Space Nine or Star Trek: Voyager.
1. Enterprise was mastered in HD. The other spin-offs were mastered in SD. There is no way for CBS to put out the same half-assed product.
2. Enterprise was the least popular live action Trek series. As such, it is hard to guess what CBS will do with the other series based on this one.
I tend to agree with your reasoning for the most part. But what makes me wonder about the amount of money that CBS will be willing to invest in DS9/Voyager is the fact that both seemed to struggle in strip syndication.
Neither series seemed to have much life after their first runs here in the States.
Well at least in the UK all the seriers (minus tas) are still runing (at least for sky costumers, I can't comment on virgin /OTA). I'm not shore if the US or the UK is representative for the reste of the world so if someone else can comment on this point it will be helpfull (unless someone at CBS can commennt directly)