I've been canning pumpkin puree from back when they DID "officially" recommend it! Never had the slightest problem. 70 minutes for pints, and it stores amazingly well for up to 10 years (no real changes in color, texture or flavor, stored in a dark cabinet in a cool basement)
The big "issue" with them no longer officially saying that you can can pumpkin at home is density, and the tendency for people to take short cuts. As long as you properly vent your canner, and do a proper hot pack (if you're trying to do a large canner full, this will probably require cooking some of the pumpkin ahead the day before, and then reheating it all just before packing it into the jars), it's perfectly safe.
Summerthyme