Firouzja played this line in an important tournament this year. It's clear that Nepomniachtchi was expecting it, and he came armed with some fine preparation.
1. d2d4  1... d7d5  2. c2c4  2... e7e6  3. b1c3  3... c7c5  4. c4d5  4... e6d5  5. g1f3  5... b8c6  6. g2g3  6... g8f6  7. f1g2  7... c5d4  8. f3d4 