Should recsystems handle interactions of users it's not currently assigned to
Currently all recsystems receive notifications for all users' interactions with articles, whether or not they're assigned to that user.
At some point I think we decided that should be true.
However, the reference implementation does not call contestant-provided on_interaction
callbacks unless they are assigned to that user: https://gitlri.lri.fr/renewal/recsystems/blob/4869a1efb0642157d612087e3d776506d2e1f403/renewal_recsystem/basic.py#L224
@hayj do you have an opinion on this? Should recsystems be looking at the activity of users they aren't currently assigned to?