In my experience, updating via LG Support Tool wipes everything. I am backing up all my data right now. Hopefully towelroot still works on this version.
EDIT: So I just finished the update via LG Support Tool. My data was left intact, but stuff was broke anyways - probably from using system cleaner app and then not having root after the update. So I am doing a factory reset anyway and will start all over. I expected it to be wiped anyway.