Hi Heather,
I appreciate the emphasis placed on the "why" of this activity, I think it was conveyed clearly and if I were a student I would understand the reasoning behind it. I hope this will minimize resistance, simply stating that this is an "essential skill" and that they can use this in future classes as well.
I think this is a great activity, and if it's safe to assume that these students are geared more toward "scholarly" activities, I would tread with caution around social media. Being a high achieving academic myself, it took a long time to shift from formal papers to digital assignments and blogs as a student. Of course, now I am hooked, but that took years and many baby steps and encouragement ;)
I would present the information also in a creative format, perhaps in a more formal Prezi (https://prezi.com), in addition to a word doc. Some students may still prefer to have hard copies though to read as their time permits. Hope this is helpful.
Viviana