Weird/random idea for AST to make one ability actually...have a point:

[MintnHoney]

Gameplay-wise, Undraw's niche original purpose was completely lost when Minor Arcana was introduced, and any niche point to Undraw (the only thing I can see is to attempt to preserve your seal structure if you can't or don't want to use Minor Arcana and want to hit a button instead of terminating the held-card effect) is currently negligible. With that in mind, I don't think Renathras' idea is bad, personally. It would give Undraw a reason to exist nowadays, and we could say, thematically, it fits because the AST has chosen to toss that thread of fate aside and chosen to take destiny in their own hopefully-more-capable hands.

However, if it were me, I'd have Undraw create a random effect on the battlefield, as the AST has chosen to leave things in the chaotic hands of Fate, rather than try to make a more controlled (and subdued) tug on the tapestry of Fate directly.
Not-necessarily-balanced-and-off-the-top-of-my-head example effects could include: 20 Potency DoT effect on all creatures (including allies) in a 30-yalm radius [can be removed with Esuna] for 2 minutes, 125 potency lightning strike on all enemies, a sudden vacuum pulls all enemies into a position centered on the AST's original position 3 seconds after using Undraw, 100 mp regeneration effect on all party members for 30 seconds, Main Stat + 10% for all creatures (including enemies) in an AoE around the user, Main Stat - 10% for all creatures (including enemies) in an AoE around the user, and a chance to create a 30y field of falling stars for 1 minute that creates tiny AoE circles that deal 10 potency damage at a rate of 1 circle per second in a random spot within the field effect.

Or something like that, with perhaps many more random effects.
But it'll likely never happen in any capacity, and I really just expect that the best they'll do for Undraw is to have it reduce the cooldown of draw by 40 seconds, one day, so that the player can make sure they're ready for the 2 minute meta burst windows.