We used to step sleeve the damaged bores, that is - we bored the original damaged cylinder leaving a small approximate 1/4” of original cylinder at bottom of bore for sleeve to sit against which stopped it from moving down, the cylinder head and gasket stopped it from moving up.
The only thing I can think is that they didn’t use enough interference fit on sleeve and someone was worried it would move and welded it at the bottom. I would definitely have it pressure tested to make sure that it has no leaks if original damage went through to water jacket area.