If we select object with reference fields for a bulk change and change that reference field, the bulk change preview is not correct:
The chosen value for the reference field is not shown, instead it says "no reference set". When applying, all changes are applied correctly.
When changing the reference, only the new reference ID is displayed.
Did some testing. The preview works now, but the editing of reference fields on the object edit page is broken.
Tested again. After changing a reference field of a test type to set a reference target to multiple types I cannot select a reference in object edit / bulk change edit mode anymore. The dropdown is empty.