This area is best addressed with fillers and not botulinum toxin. The botulinum toxin can weaken important muscles that help hold the cheek up. That is nice doctor speak for saying that it can definitely cause your cheek to droop. That effect can last for month. Time is the best fix for this. Don't have this treatment again in the future.
Botox injected correctly in the correct area of the crow's feet should not cause the cheeks to droop. However, if large number of units were placed this can cause some migration and possibly affect the cheek muscles thereby causing a droop. In addition, Botox injected incorrectly ie lower than the crow's feet area will also cause the cheeks to droop.