Unless you've also removed the valves/heads from the pistons, there's this thing called compression that occurs at TDC for each piston stroke; on a TDI motor it is a relatively high compression ratio, since it is a compression-ignition type engine, where the compression generated heat actually ignites the fuel, etc. Watch some videos on how shops replace the timing chains/sprockets/components; you generally won't ever see them 'turning the engine' after since that is something they would do prior to disassembly in order to ensure the engine isn't locked up/damaged internally prior to swapping out all those expensive parts for new, etc.
They do most definitely examine all of the timing parts/guides, tensioners, etc., they take off for damage and look for any missing pieces of the guides or other parts that may have collected at the bottom, etc.
Good luck!