While it seems logical to reach that conclusion, I highly doubt it, based on my experience with non-spunded repitching. Several years ago, I took a lager yeast out to 25 successive batches without issue (over 2.5 years). I didn’t have the spunding aspect in my situation, but I wouldn’t conclude from your situation that the yeast that you harvest have less vitality, just because of floccing out before the final points are dropped - however, if you also were fermenting under pressure for the full primary fermentation, then my conclusion would differ, as the pressure should have some affect on vitality and suppressive effects, generally. I would expect some potential for genetic drift in a pressurized fermentation set up, less so with mere harvesting than spunding.
But, try it out and let us know your results!