This thread was helpful advice for me, as I had the same problem. However, a new problem has cropped up. I found a great little widget here — https://floatingsun.net/blog/code/wordpress-widgets — it creates a list of Related Posts but using UTW tags instead of the methods of other posts. However, unlike the tag archives which seems to know to include only posts and not pages, this widget includes pages.
Disabling the automatically include primary tag links had the correct effect of stopping tags from displaying on the pages — but it seems that as long as I’ve got UTW set to automatically add the Categories as Tags, it adds the Default Category into the records for each Page — even though there is nowhere on the Pages to modify Tags anyway! UTW obviously keeps adding this info, hiding it in the records for the Pages, and this widget is picking it up.
Any suggestions?