Agreed that exact phrasing of the intended meet-up at the festival matters.

"Would be great to see you at the festival" sends a very different message than making an actual plan and confirming perhaps a day in advance that the two of you will meet at the entrance, at 5pm, tickets in hand, to check out to the festival together. Nonspecific plans are often (unfortunately) no plans at all. And, that is on both of you, as you both could have initiated a specific plan for those logistics if you were invested in actually seeing each other.

So, agree that you are justified in feeling hurt because your expectations were not met, that does suck. But, better communication in the future can help you to avoid that with her, and/or other women (and/or any friends).