Deadlier? Well 122mm piggie is larger than 105mm which means there is slightly more TNT and slightly larger jacket means bit more snarpels spreading around. Also compared to the most western 105mm, the 122mm D-30 derivates (eg. all "modern" 122mm) have longer range.
The vehicle in the pics seems to be the Type 89 tracked SP systems turret (in effect similar to 2S1) put on top of the new 8x8 wheeled vehicle. There's been past prototype projects with sligtly different turret on top of slightly different 8x8 vehicle.
Why they are producnig this system is bit odd. The SH-2 truck-mounted system is IMO much favourable system but apparently it was again only export porduct not seeing PLA service