It will be an issue if they try and make the top athletes compete in it, for WAG especially. May work a bit better with MAG where there isn't such a small pool of gymnasts tending to be in almost all finals, albeit maybe that will reduce in WAG anyway with Rebeca dropping floor and Simone on hiatus/finished.
If it's to work, the best way would be to let countries use their whole roster. So assuming for the sake of argument that it's VT/BB/FX for the women as with Euros, and focusing on the women as I'm more familiar with them, I can see how this might've worked in Paris.
That format is tailor made for Ruby Evans, for example, and she made no finals after TFs. If Jade had been sufficiently recovered from the flu, it would've suited her too, and if not then Hezley is the obvious choice. Those are Zhou Yaqin's events, and she wasn't in the AA final. Andreoli also. In the best case scenario for the mixed event, it could be something that teams factor in when choosing athletes and lineups.
However, if either the rules or the programmes themselves approach it as right, another competition day for Biles/Andrade/D'Amato/Black/Kinsella then yes, hard to see how the consequence won't be even more visibly exhausted performances in EFs.
But maybe even without this, it's time to talk about teams being a bit more strategic about how much they use the best athletes. We all saw, for example, Alice Kinsella's EF performances last quad being much less tired when she'd not done all events in a TF and AA too. Then there's the question of whether Simone might've had more left in the tank by the final day in Paris if she'd sat one or even two events in TFs and the US had won by a few tenths less.