When it comes to content and collaborating with creators, ALWAYS have an extra 1 or 2 creators than you need.
You are working with humans who have their own lives and things pop up (trust us we do this daily we've had covid, the flu, pets getting sick, problems with deliveries, products breaking, creators travelling, creators moving house, fires, floods, sick family members, creators breaking limbs and the list goes onnnnnnn) these are just a small list of issues that can arise with working with creators.
Having a back up will allow you to have enough content should 1 (or god forbid more than 1) creator pull out of their content commitment (you don't want to be scrambling for content). If all creators pull through and send in content then great, you have lots of content to spread out for your posting schedule (too much content is such a lovely problem to have!)
Trust me, organise that extra creator!