Yes, because the pitching rate has to do with the OG of the beer and is directly correlated to the viability of the yeast.
For example, assume the viability is 100% and the pack contains 100B cells, but the beer you are brewing requires 300B cells for the correct pitching rate you still need a starter to get your 300B cells.
IF the yeast viability is 80% then you would need to grow 20% more cells to achieve the same starter for correct pitching rate.
Most liquid yeast packs will tell you that they are good to direct pitch up to 1.050, that assumes 100% viability and generally is still a little under the required pitching rate.
You can go to: http://yeastcalc.com, plug in the pertinent numbers and determine the required pitching rate for any beer you want to brew.