No I have not had a chance to look at coordinateUncertainyInMeters.
Probably though footprintWKT would be more meaningful to look at for gridded datasets, but I actually did not know it existed before writing this blog post. https://terms.tdwg.org/wiki/dwc:footprintWKT
Unfortunately, I don’t think footprintWKT is used so often. Around 20M records have a not NULL in the footprintwkt column. I estimated at least 75M occurrence records are gridded. Also having a not NULL in footprintWKT does not necessarily mean the record is gridded above a trivial degree.
You can see that some gridded datasets do have a square footprintWKT.
Like this point form EBCC Atlas of European Breeding Birds