Hi Michael, great to hear from you again!

Please reference the Conflation plan section of the UtahBuildingsImport documentation to see why existing buildings may have been deleted: osm.wiki/Utah/UtahBuildingsImport#Conflation_Plan Each deleted building is individually reviewed by hand for footprint detail, placement, and tagging, and a judgement call is made on the best representation. Tagging is also merged between the two footprints. Conflicting tags are also reviewed for whichever is most specific and accurate. This is what was done in this case, where many of the existing house footprints only were tagged as "building=yes" and were simple rectangular polygons.

I posted to both Imports and Imports-us mailing lists. The email to the Imports list was sent on January 6. Here's a link: https://lists.openstreetmap.org/pipermail/imports/2018-January/005333.html
I was not aware I had to include links to both emails in the documentation.

Best regards,
Jay

Hi Michael,

Thanks for your interest. I have satisfied your requests.

If you are interested in contributing to this import, I would be happy to brief you on it!

Regards,
Jay