[Update: I did not read the original proposal carefully. I mistakenly believed this was a mandated regulation and not a voluntary one, so some of the points in my post do not apply. However, I still oppose it for mostly the same reason: if consumers wanted this type of label on their products, then we we would likely already see it. I am also skeptical that this is being initially proposed as a voluntary program, but…
I don't think this is true. Security issues don't matter until they do, and consumers -- by which I mean "people" -- are notoriously bad at estimating risk for sufficiently rare outcomes.
To take a common example, insecure internet-connected baby monitors can literally give strangers video access to your home (not to mention your child, although we don't need to resort to "think of the children"). I think most consumers make purchases with the reasonable expectation that the product isn't going to violate their personal security without them knowing.
As a concrete example to the contrary, even many laypeople I know consider home assistants like Alexa to be too risky -- they don't like the idea of being overheard and monitored by some unknown "other". And that's almost literally part of the product description! When consumers are aware of these issues, they do care. The idea that they currently purchase as though they don't is confounded by a lack of awareness on the one hand, and a reasonable expectation to the contrary on the other hand.