As part of patch 6.0, Final Fantasy XIV players will start to see some changes to Scrips and Allagan Tomestones. The FFXIV team took to their website today to outline those changes, giving players plenty of notice before the patch hits.
Effectively, Allagan Tomestones of Poetics will still be an end-game currency for players to use, provided they aren't being used for Endwalker-specific content. New Tomestones will be added to the MMO, which players can only get once they hit level 90, the new cap brought on by Endwalker. Allagan Tomestones of Allegory and Revelation can be exchanged for Poetics one patch 6.0 releases, though Phantasmagoria will be exchangable for Allegory (with the currency being removed entirely from the game once 6.0 releases). You should go exchange those for Allegory tomestones before Endwalker releases, according to Square Enix.
As far as scrips, yellow scrips themselves will convert to white scrips once patch 6.0 hits servers, and red scrips will cease to be. Players will be able to exchange yellow scrips for white ones when the update happens in Revenant's Toll, among other locations.
Essentially, as Endwalker takes shape in late November, you'll want to start thinking about your endgame currency and get those exchanged well in advance. You can check out the full post here. Also, if you missed any of our Media Tour coverage, including our interview with Naoki Yoshida, be sure to catch up on our Final Fantasy XIV game page.