Would the stored cord blood stem cells still be useful after so many years?

Stem cells that have been cryogenically preserved remain viable for decades. It has been confirmed that cord blood stem cells were still viable after being frozen for over 23 years.

References:
Broxmeyer, H.E. Cell Stem Cell 2010; 6(1):21-24 Mazur, P. Science 1970; 168(3934):939-949 Nietfeld, J.J. et al. BBMT 2008; 14:316-322