The current state of HomePlug is weird, the organization behind it dissolved in 2016 and basically dumped the spec on the table (they made it public domain). Since it's closely related to IEEE 1901 it doesn't seem likely that HomePlug will ever "go away," but it's also not going to get better. So I think it's definitely fair to say that G.hn is the replacement, in that it's more actively developed, but HomePlug devices remain plentiful on the market. IME HomePlug devices are more commonly sold in the US than G.hn powerline devices, but I get the impression that things are different in Europe.