Where I come from, blocks aren't bored until the new pistons are on hand so that all can be properly matched together.
And the rings also have to be properly sized as well.

If the crank and rod bearings were marked as to where they came from and assessed with plastigauged and found to be within spec,
then reusing them is fine, as long as there aren't any marks or grooves.
Back in the day, we reused factory bearings all the time as we often had better clearances than with replacement A/M bearings.