When I requested that we note paywalled sites in links, the practice was becoming popular and there were more and more, it seemed, every day. At this point, I think the main paywalled sites, NYT, WaPo, WSJ, are well-known, so I don't see any point in including that in the link title any more, unless the you just want to. If you post an unfamiliar seldom-linked site, which is paywalled, it still would be common courtesy to note that so that an interested reader doesn't waste time...