Interesting information. It roughly agrees with the label on, IIRC, the Lalvin 71b packet, which says to wait no more than 45 minutes after hydrating before pitching.
I broke that rule once. It didn't kill all the yeast. They still ate all the sugar in my mead. SO IT'S ALL A LIE!
Er, no, so it's probably not the end of the world if it takes longer, but it's always good to know what the best practices are before you go violate them.