I think they did report it first. But IMDB change regularly, it's not the most reliable for
new roles sometimes as it can be a while before something is updated and sometimes something gets posted based on rumours. But the site can be right sometimes, it's just better to verify against something that is definitely reliable.
Perhaps it was originally intended for Brenda to appear in the pilot, she may appear right at the end of it, or the storyline created for her may not have fitted with the pilot and it was decided she'd appear in episodes after that and IMDB haven't updated the information.
Guess we'll know soon enough
*hugs*
xoxoxo