They'll never reinstate those Legacy achievements, because the whole reason they're 'Legacy' ones is because they were for content that disappeared in the change to ARR (like, the travel ones for visiting every 1.0 aetheryte and aetherial gate in pre-Calamity Eorzea), and hence, are no longer relevant.
I'm also curious as to why they've only now decided to shut down the old Lodestone, as it was already archived anyway (trying to save on network bandwidth, or just trying to erase all traces of FFXIV's sordid past?). Ah well, I backed up the relevant pages for it long ago so even once it's been deleted, I'll at least still have a record of it (plus, there's always the Internet Wayback Machine on the Internet Archive to view it).
