Yes a 2cm difference is a big deal. Now the question is, is your current saddle position right where you want it to be?

Moving the saddle forwards will place more weight on your hands/shoulders/arms. 2cm forwards is quite a change. Nominally I wouldn't be moving your weight forwards on a touring bike. How much clamp setback is there on your current seatpost? A typical standard seatpost has about 25mm of clamp setback. Some have zero setback, some seatposts can have 40mm of setback or thereabouts.

Anthony