The guide may be out of date, but with a date of December 2012, it is more likely that it was mistakenly left out of the guide than outdated (Dell's documentation doesn't get updated often enough for there to be a version newer than 1 month old).
However, given the fact that with the latest BIOS installed (did you also update your iDRAC??) it does not boot with it, it would probably be more likely that the Parts and Upgrades site is incorrect (after all, you have before you a system that will not take it).
Two other possibilities:
1. You did not update the iDRAC along with the BIOS ... this can make a difference.
2. There is mention of a T610 II ('II' identifier would be on the upper-left corner of the chassis or visible on the OMSA>System>Main System Chassis>Information sub-tab), and while nothing is said specifically one way or another, it is possible that only revision II supports it.
May be worth a call to Support for confirmation on exactly what will/won't work. Just let us know what you find out.