Are the tiles they provide in the terrain tile set the same that are in the Org. core set, op. seelowe, and op. cyclone (combined)? What about the other terrain as well?

IIRC, the tiles provided in the espansion pack lack the shore/submarine ones from Operation Cyclone and feature a slightly different assortment of building tiles than those from Operation Seelowe. However, they also features some tiles replicating the poster maps from the Revised Core set.

The tile set contains:

6 tiles are snow/industrial

3 tiles are snow/water&bridge

3 tiles are industrial/Water&bridge

1 3x3 square building each side has a different entrance layout.

1 2x3 square building each side has a different entrance layout. with a machinery/smoke tile and a 2x1 machinery/ammo creates tile

1 tile of ramp/walls

Meaning it comes with none of the SeeLowe buildings. It's basically the original and revised core set tiles. With Cyclone's ramps and a bit of SeeLowe's smoke/obstacles squares.