The ICO won't be a member of the EDPB post-Brexit which will definitely have an impact, but not a catastrophic one. The bigger problem is that the UK won't be

The ICO won't be a member of the EDPB post-Brexit which will definitely have an impact, but not a catastrophic one. The bigger problem is that the UK won't be able to be certified as having adequate protection due to the Snooper's Charter (or, rather, any adequacy decision will be almost instantly sent for judicial review).