I think you are mistaken. That is the RDB-C, the Canadian model has the standard furniture but with a 1.5” longer barrel than the stock 17”. He probably bought that model as they are available down south and have a 20” barrel so are already NR. I don’t believe it’s California compliant without the bullet button though? The rifle grip stock started with the RDB-S, not necessarily for Cali.
I think the lack of a pistol grip gets it around needing a bullet button. I'm not fluent in their gun laws though.
I see ebolas point though. Sell the rdb-c first, so everyone who needs one NOW buys this one, only for many to buy the normal version a few months later once they're available and they realize the -C is an ugly duckling....
That said, I would love to try both side by side. I could see me preferring the -C due to weight, but then again this would be a coyote or survival gun for me not a 3 gun toy or anything - wouldn't want to deal with a malfunction in the middle of a 3gun match or anything with one of these.