Is the "this cannot be uninstalled" a new feature?

in some products in 5.1 there is a "this product cannot be uninstalled" notation

I have never seen this before. Is this a new feature for 5.1? I think it is a nice touch.

it's a warning that the product is not upgraded to current standard of Plone installation. I think it's displayed when there is no 'uninstall' directory in the profiles subdirectory (this directory contains the instructions to uninstall the add-on)

thanks, i think it's a nice feature. It lets people know what they are getting into