What do you think about people who RSVP that they are coming to a party weeks in advance

And then text you one hour before saying “Oh hey I meant to tell you before but just didn’t get to it. We’re not coming. We actually had a conflict and couldn’t attend, sorry for the late text”.

Or who simply change their RSVP to not coming 1 hour before with no reason.

Or who say “Oh hey I’m busy cleaning and can’t come, sorry” one hour before.

Are these people irresponsible? Should I let them know it?