Yes, to both statements. However, duplicate submissions are starting to become shadowbanned (if the intent is to manipulate SERP), while having your site link

Yes, to both statements. However, duplicate submissions are starting to become shadowbanned (if the intent is to manipulate SERP), while having your site link on spammy sites is simply a downrank in relevant metrics. The other corollary is that these sites will likely not have substantial enough metrics -- owing to the amount of outlinks they have to all sorts of low-ranked content -- and so posting your site on them for purely SEO purposes is misguided. They're better used for organic traffic.