Yes, that’s the idea.
Exact same situation here in suburban NY. Audience sits in the bleachers, students on the field, plan B indoors if it rains. It’s been the tradition for most schools in the area for decades, though a few have switched to indoor venues, such as a local concert hall. At DS’ (only child) graduation, it was DH and I, plus his only living grandparent and my sister (single with no kids, wanted to come). He gave his 2 extra tickets to friends who could use them. We had a party at our house a few days later with extended family and some close friends. Announcements are unheard of around here.