Do they seriously believe they have material for another show
Why not? All it requires is imagination and effort.
or are hoping to keep cashing in on the Star Trek franchise because it is a known money-maker?
If there was no expectation of making money, there would be no chance of it happening - on TV or in theaters.
Here's my bet: within a few years, Trek will return to TV. It will key off the success of the movies, so it will take place in the 23rd C. It might even draw some of the movie actors to TV, as regulars or at the very least, guest stars.
Most likely there will be new characters as well. It will be a traditional Starfleet/starship-based going-boldly scenario, but without the re-tread episodes that made VOY and ENT so tiresome. It will be more serialized than TOS but not 100% serialized.
If there are any direct references to TNG, DS9, VOY or ENT, they will be minimal. Don't expect a lot of guest stars from those shows. The odds of the new series being any of the usual fan notions - Federation Civil War, post-Dominion War, Fall of the Federation, Birth of the Federation (but done right this time), Klingon-centric, Romulan-centric, based on novels, based on fan films, etc. - are nil. All those are too exotic and require too much previous knowledge of
Trek, which at that point will have a vastly increased fanbase of people who haven't been following along all these years.
JJ Abrams' success with Trek will provide the clout that gets
Trek on TV (if he wants it) so he'll at least nominally be in charge of it, tho he may hand it off to others, a la
Lost.
The least predictable part of this equation is where it will air. CBS would have first dibs but it's the wrong audience. NBC or Fox would be more right - even so, can space opera survive on network TV anymore? Basic cable seems too puny, and premium cable is too adult in its expectations and image for family-friendly
Star Trek.