The good news about planning a first visit during that week:
DLR should be on the Peak Schedule, i.e. longer hours, fuller staffing, more/all rides running at full capacity, more entertainment, nighttime entertainment running every night, etc. This is good because it means the parks will be expecting and be prepared for crowds. When the parks are prepared for crowds, things run much more smoothly and you don't really feel the crowds as much as you'd think you might. June weather is usually pretty nice -- cooler in the mornings and evenings, warm in the afternoons. Grad Nites are finished (usually) by that time. Lower AP blocks for DL will be good for the summer after 6/20.
The not so good news about planning a first visit for that week:
In all probability, DLR will be very crowded because of SWGE -- either already open or opening that week.
As all the previous posters have said, crowd calendars do not really work for DLR. In fact, they are notorious for not being reliable, especially after DL's 60th. But, we tell people here not to try to second guess the crowds (you can't), but to choose the time that works best for them. Then come here to do the best research and planning for your trip. Do your research, make your plans (plan a & b), bring your patience and a positive attitude, and get ready to have a great trip!