Guys will the new ccmg 9mm lower that is used for the radial delay system still be used for blowback? The reason I ask is they still look the same as the old lowers?

You can call Cmmg and ask them directly for the answer.

     660-248-2293

I presume you are referring to the lowers that take Colt mags?
If so the lowers are the same you just swap parts if you want to use the RDB system or not.
EX: Pictured below is what you need when using the RDB system in their straight blowback system:
https://cmmg.com/parts-kit-mk9-9mm-radial-delayed-blowback-colt-metalform-mags
Note this is for Colt / Metalform mags.  They have another kit for use with C Products 9mm mags.




If you want to understand the why's or do it yourself, I modified one of my straight blowback setups to use my unmodified Colt mags before this came out here:
https://c3junkie.com/?page_id=374

However, I don't use it anymore since I like Endomags the best and just use a normal 5.56 lower.