Thanks for editing and thanks for asking. Based on your reply, I think you realize why they were not needed. But here is the explanation. Ways that use building:part are used for tagging parts of a building differently than the rest of the whole. The building parts that were deleted only had a tag of building:part=*. No other tags were provided. So a single way for the entire building is most fitting.

As a side note, I came across these ways because they had invalid values for building:part. They were tagged with a value of "1" when it should have been a descriptive value or "yes".

I'm guessing you're already aware of all of this. But you asked :-)