The shop should use a good sleeve sealer on the sleeve but the block will determine if it will seal up the sleeve or not.
I've had one 400 Mopar block that was so thin (.032 to .015 due to core shift) on the cam side of the driver side of the block that it would not seal up after cracking the block there
We tried sleeving all four cylinders also, no luck. That block was junk
Due NOT weld it up