Your guide basically summed up the area:

"The area we will be hunting is near/along the Johnson River in 20D. The guide has told me we should see several legal bulls during the ten day season, and that there is a good chance of seeing grizzly. Healso told me that they do not normally see black bears, and only rarely see wolves. He said we would probably hear wolves and evensee their tracks, but it was notlikely to see them."

There are lots of grizz in the area as well as wolf. Wolves are hard to spot due to the terrain but they are there and in good numbers too. Years back I watched a pack go after a cow moose on the Johnson as it enters the Tanana.I mainly hunt & trap 12 & 20E as I live in the area. Yeah you should see moose and you'll be there as the rut starts getting in to full swing. I called in two bulls & a griz last year (about the 15th) just sitting on the deck of my cabin which sits in theTMA. I was just playing around enjoying the evening. Yes there are critters there. Trust your guide.

Good luck on your adventure