Well, if we're doing insidery things...
A person a know (friend's uncle's lover lololol etc.) who was adamant that Rockstar won't reach a GTA 7. I was obviously all jenniferlawrenceOK.gif, but this person has worked in game audio for 20+ years and had friends in Rockstar (as well as all over); apparently, their tools are world class, particularly their audio engine/pipeline/technologies, and they could easily sell that technology for over 2 billion. Combine that with the sale of their other top-class technologies, and they have a quick and easy few billion in a very quick timeframe - much easier money than making GTAs (V took half a year to get 2 billion in revenue, not profit, if I recall, and it's much easier to sell tech than make a product which is reliant on the whims of critical and commercial success or failure). From then on out, R* just become a tech house and take the easy road.
I can't say I believe it, but then I know a hell of a lot less than this person and if what they're saying is true, it certainly seems the most profitable and safest route for a higher management suit to take.
Oh, and I saw every cancelled Rare game from the last 10 years ¯\_(._.)_/¯