Ok help me out here peeps!

My inlaws have an annual family BBQ every year. Last year it was in September. I emailed my mother in law in June asking her when the BBQ was and to please let us know so we can plan to be there. We live in Utah, they live in California. She emailed that is would be in August and she would let me know in advance.

Fast forward 2 weeks ago, and my husband gets a Facebook invite (not very reliable cause sometimes you don't get a notification for that). I didn't get a Facebook invite or email or anything. The BBQ was yesterday. Who in their right minds invites someone to an out of state FAMILY BBQ two weeks in advance?

So am I wrong to be upset about this? (and I know I make mountains out of mole hills, it's my diva personality)

ETA if you vote mother in law is right please help me understand why she is right. No voting and running!