Co-creation is not an inherent part of data-driven policymaking. It is perfectly possible (and widely practised) to conduct data-driven policymaking without involvement of other stakeholders. Please do not produce murky definitions of concepts.

The real issue, regularly highlighted, concerns the availability of data. One case is that the needed data is simply not collected and the level of granularity needed or targeted. Another case is that data is actually collected but since it is an asset by those who collect and detain it, it is not shared or shared at a (high) cost. Policy making typically would like to rely on open (and free) data.

Co-creation may not be inherent, but it may be increasingly inevitable. The European Commission talks about "the advent of co-responsibility with citizens and businesses (co-design, co-production, co-evaluation, etc.)". Reference: European Commission. (2017). Quality of Public Administration A Toolbox for Practitioners.

Co-creation is a very nice and promising concept. But many initiatives up to date have failed; actually the majority of them. IMHO it's due to the fact that direct co-creation is extremely difficult. MAybe "indirect" co-creation, e.g. through opinion mining and sentiment analysis in dedicated sources could do the trick. Yet again, you have to motivate a representative sample participate in these sources...

As long as one secures data availability and reliability, data-driven policy making is the only way to go. However, both aforementioned preconditions are very very difficult to achieve.