Fleury didn't take two weeks off. The WJCs finished Jan. 6. It took him a few days to get things in check before he arrived in Pittsburgh the following Sunday which was the 11th. He didn't play for a few reasons:
1. You don't throw a 19 year old goaltender immediately into the NHL after not playing at the top level for so long, particularly with no practise
2. Even at practise, it would take time for Fleury to adapt to the standard of shots that he'll get in an NHL game (please, no jokes about the Penguins not being up to NHL standard)
3. Jean-Sebastien Aubin was playing the best he has in three years. Not starting JS wasn't an option.
Its not an issue of him taking time off. Starting Fleury simply wasn't practical at the time.