I have some thoughts on this too.
1. I surely hope that this is implemented in a way that by default the funds go back to original sender (and not the gift card app developer) after that period ends.
2. I would let the gift card funder decide whether the gift card expires or not (and the expire date, if any, has to be printed on the card). And I'll tell you why:
* if I want to give out money at some conference maybe I'll set up an expire date because I don't want my money be lost by people not interested to redeem it
* if I want to give it as a birthday present maybe I'll not set up any expire date because maybe my friend wants to keep it as a souvenir
Plus, it has to be stated clearly whether it's custodial or not (if it's custodial you may have trust problems and maybe also problems with financial institutions).
Sorry, I find the existing paper wallets (if generated properly, safely) and collectibles good enough for the job.
I mean that the recipient will have to install (and rather quick!) his own wallet, learn on his own to keep it safe (which is not gonna happen) and redeem that money. So one more level of complication.
But yeah, I may find easy the technical bits other don't gasp, so maybe my feedback is not that relevant or wrong. New projects - if made well (see my thoughts) - never hurt to be more.