Hi, I have created a Voki in my free 15 day trial to try it out. I have embedded this Voki in a Google Sites page. If I decide not to go ahead with the paid subscription, will the Voki I created and embedded disappear?

No it will not disappear.

But there will be a limit on how many Vokis you can create & save, and you will no longer have access to the embed feature.

Furthermore, any student's logins you may have defined and any class assignment pages will not work, and saved Voki Presentations will not play.

Hope this helps,

Gil