Dry wouldn't have been affected, but freezing the liquid yeast probably noticably reduced the number of viable cells. So you you had a longer lag while the remaining ones grew up their numbers. For now, it's fermenting, and everything may be fine. I'd wait and see. Only if the fermentation stalls, or underattenuates, you might want to consider pitching some more yeast -- preferably a starter at high kräusen -- to finish the job. RDWHAHB.