It should be possible, but it will definitely require some work.
First thing is that you will need to install Ubuntu 18.04 on ROSbot.
Second thing is that CORE2 controller for motors and other low level components is based on hFramework - it does not support ROS2. You could use ROS2/ROS1 bridge to establish communication with CORE2 controller. Other solution would be to implement custom firmware based on micro-ROS framework.