The new build for the A70s comes with version number A707FDDU3CUC6 and the firmware for A90 5G has version A908NKOU3DUC3. Both come with the March 2021 Android security patch.
Samsung Galaxy A90 5G
The Galaxy A70s is receiving One UI 3.1 in India and A90 5G in South Korea at the time of writing this. Unless major issues arise the rollout should expand to other countries soon.
If you own either of these smartphones and haven’t received an update prompt yet, you can try checking it manually by heading to the Settings > Software update menu on your device.