Does the law, as implemented in their local member country, state that they have to state the salary range on that sort of post. There are a number of possible loopholes I can think of depending on how their regulations are written: it is an international posting, it is an informal/prospective posting, the information is available on their site (which they may or may not link to) etc.

Also “in the last year” means only ~50% of that time is covered by when enforcement started.

Some countries have yet to pass any legislation too, this happens quite a lot if you look into past EU declarations, so companies there might be using that as a loophole to act as if not yet be effectively covered (in theory they could be taken to court over it, but that is can be complicated, or at least expensive, when there is no local legislation yet, so in practise it is far less likely to happen). What action will be taken by the EU to push things forward, I'm not sure, presumably there is some sort of fine for extended non-compliance? The question of who you are advertising to and where from can get a bit complex if you are a company in a member state that has not yet enacted anything, especially when you operate out of more than one territory.

Most of the jobs in that HN thread do give a salary expectation (though a few with a very wide range, which might be outside the rules, but they were US anyway so not covered), I don't think I saw an EU one in my quick scan that did not (at least one UK one, but again those are not currently covered by such rules).