I currently have no info on my portal, but the note may be in reference to the pdf for Instructions to Applicants Offered Admissions, which does provide a lot of information on things to do before R-Day. Also, the cover letter in the admissible mailings area states, "In the coming months, we’ll send information and videos to you via your candidate portal to inform you about military training at West Point and to show you how to properly prepare for the rigorous challenges of Cadet Basic Training. We’ll also notify you of specific items needed when you report and the time you will report on 2 July, Reception Day."
As far as specific reporting times, packing lists, etc, I haven't heard anything.