After collecting information via web searching, the comments above, and an additional call to BOA, I have concluded the following to the best of my knowledge.
Zelle Transfers are final. Irreversible.
As Jay mentioned above, funds are subtracted from the sending account before the transfer is made, therefore it eliminates sending funds that do not exist. I validated this information with BOA, and the BOA representative said that once a Zelle transfer is initiated and the receiving party has received the funds, it can no longer be canceled. Funds received by the receiving party is credited immediately.
I will note that the BOA representative was a BOA representative and not a Zelle representative. I say this because the representatives seemed to be slightly weary in answering my questions about Zelle, as if he was looking up the information as we spoke.
If someone is reading this and plans to transfer a huge amount of cash from a highly likely malicious user, I would recommend contacting Zelle or your personal bank directly to further validate this information. Zelle, from what I can find, is a fairly new technology. I could not find a Zelle contact number via the web for questioning, so I can only rely on the knowledge on my BOA representative.
Adding in additional information with new sources from comment below.
As long as both parties are previously enrolled, it is instant and irreversible. This can now be confirmed with direct cites: Can I Cancel a Payment and User Service Agreement (section 11 last paragraph) However If you have not properly registered your email or phone number ahead of time, you run the risk that they cancel the transfer before you complete enrollment. --emkman