Perhaps, meeting/conference organizers would consider using social media or Internet facilities a bit more.

Surely, text messages can be sent to all participants (of the meeting) to forewarn of the change of venue, time, ...

But, meeting room booking (system) should have been better.

บทเรียนสำหรับคนจัดประชุม ;(

We can't get ahead, if we create a lot of hassles for those who are coming with us.