So what was this all about and why was it demolished after such a short time? I tried to search about it and kept finding it labeled as a temporary structure.
According to the official statement of Masjidil Haram, that mataf bridge was indeed just temporary bridge that assembled while waiting the Masjidil Haram expansion project finished. Now the new area for tawaf has been finished, and the mataf bridge disassembled because no longer needed.
The Mataf bridge was a temporary structure constructed in 2013 and dismantled in 2016. During that time, the external area was being renovated and this bridge helped people perform Tawaf. Below is an old picture from around 2014 and it shows the circular bridge in the center. One side of Masjid Al-Haraam was still under construction at the time of this picture.
June 2014:
September 2015:
This picture shows part of the renovated area:
This video illustrates the Mataf expansion work
Now that the external expansion work is almost complete and open for Tawaf, the temporary bridge was no longer needed and it has been dismantled.