>>27742168If it is a physical attacker, then it has all of old Marowak's attacks in addition to any new additions to use.
If it is a special attacker. Old Marowak still gets these moves:
-Ice Beam
-Blizzard
-Flamethrower
-Fire Blast
-Focus Blast
-Ancient Power
-Icy Wind
-Earth Power
New Marowak being a Ghost type all but guarantees at the very least:
-Shadow Ball
If it does become a special attacker, hopefully GameFreak either a) buffs Thick Club into Light Ball boost or b) increases new Marowak's BST and shifts it around to suit the new Marowak's needs.
I doubt they will do either, so we can (safely?) assume Marowak remains a physical attacker.