I have the same problem uploading from Metashape standard (2.0.1.15925) to Sketchfab.
On the occasions in the past where I export a file from Metashape for manual upload to sketchfab, I use the FBX file format, but this currently throws the same error, although the files open fine in Meshlab (2022.02)
PLY file exported from Metashape and manually uploaded to Sketchfab works fine.
I've just tried uploading a FBX file exported from Metashape almost a year ago (version 1.8.2), Sketchfab did not have any problems with this file.
Hamish
Metashape Std v2.0.1.15925 -- i7-13700K, 64GB Ram, Nvidia RTX 2060 (driver 531.18), Win 11.