Primalist was scrapped by the original dev team due to complexity issues, so doubtful. I don't know how much data for the Sentinel AT was in the code at the shutdown, but if you look at it all it does is pair Blaster primaries with Scrapper secondaries. This drastically cuts down the work required (coding, effects work, etc...) to implement it.
Also, from a gameplay perspective, I can see this AT having the same issue Kheldian characters faced but even worse of being so horrendously slot starved.