Engagement Party

Engagement parties are typically thrown within 3 months of engagement

I would be confused being invited to an engagement party a year after the proposal. I’ve only seen them done a few weeks, max a couple of months, after the engagement. I didn’t have one personally, but we were only engaged eight months so we didn’t see a point.

Engagement parties are to celebrate or announce a recent engagement. In your place I’d feel that ship has sailed.

I would say it's already too late. I'd keep any pre-wedding events for ~6months before your wedding.