the users should be notified of how different the purpose of the two projects is compared to that of OpenCare, and:
either be asked about their understanding of it (just the first question of the new funnel could do),
or receive at least a message inviting them to read more about the project and its sensitivities
(the latter could be an entry in the platform where your considerations about the sensitivities are shared and offered up for discussion by participants as the projects evolve… the replies could then become part of the material to use for our auditing )
The above is to emphasise that the landscape of risks is different, which has a value as “informed consent” also for your research.
It’s basically a yes, with an extra action taken by community managers, so @noemi and @johncoate. Which is actually good, because it doubles up as engagement (“we are going to be doing a new, exciting project! How do you feel about us using your content for it? Do you want to know more? etc.”).