The UploadWizard marks images uploaded from Flickr, that have the 'public domain mark' as the license on Flickr, are marked as...
{{FlickrVerifiedByUploadWizard|Public Domain Mark}}{{PD-author}}

No, this is actually not the case. UploadWizard marks them with {{FlickrVerifiedByUploadWizard|Public Domain Mark}} and requires the uploader to specify an additional copyright tag.

For example, if you were uploading https://www.flickr.com/photos/swallowtailgardenseeds/18374121668/in/photostream/, you'd see the following form:

Given that we require users to input a license tag, I'm not sure if adding a template that says "This media file does not have sufficient information on its copyright status" (https://commons.wikimedia.org/wiki/Template:Flickr-public_domain_mark) would be appropriate.

Regardless, if this is to be changed, we should probably have a clear consensus of the Commons community to do so. (It can be easily changed from the technical side.)

@matmarex If the UW is actually requiring the uploader to input a license tag other than the PDM, then it's probably fine.... this came up at a DR, and possibly I misunderstood exactly what the tool was doing. There is a consensus on Commons that the PDM 'in and of itself' is not an acceptable license, but it sounds like you are saying that the tool requires the uploader to do what the template itself would ask for. If that's the case, then we can close this as invalid I guess.

there is no clear consensus for this interpretation of PDM.

In T158352#3035500, @Revent wrote:

There is a consensus on Commons

Links are always welcome. :)

@Aklapper There was an RFC in 2015... https://commons.wikimedia.org/wiki/Commons:Requests_for_comment/Flickr_and_PD_images

It's also come up repeatedly on the VPC, such as....
https://commons.wikimedia.org/wiki/Commons:Village_pump/Copyright/Archive/2016/01#Flick_and_PD
https://commons.wikimedia.org/wiki/Commons:Village_pump/Copyright/Archive/2016/03#Is_CCO_1.0_the_same_as_CC_pdm.3F
https://commons.wikimedia.org/wiki/Commons:Village_pump/Copyright/Archive/2016/12#Creative_Commons_Public_Domain_Mark_on_Flickr
There's also the content of https://commons.wikimedia.org/wiki/Category:Public_Domain_Mark_1.0-related_deletion_requests/deleted

The documentation of https://commons.wikimedia.org/wiki/Template:Flickr-public_domain_mark explains why we don't accept it. If Slowking, or anyone else, wants to insist there is not a consensus then they need to start a new community discussion to overturn the previous RFC.

But I would think that the main evidence for such a consensus would be that such files have been marked for 'delayed speedy' for close to two years now.

See also T105629 for the past discussion when PDM was first added.