Is this normal with a trust?

My husband's grandmother passed almost 9 months ago and left a trust with him, his two sisters, and his uncle as beneficiaries. We are getting nowhere with his uncle who is also the trustee in finding out information. We just received a letter in the mail asking us to sign a waiver of notice of hearing on inventory. The list of the assets on this form only showed 2 bank accounts. There is also land, a house, and investments that are also a part of the trust as we received a copy of the assets a couple of months ago and that was all listed. The letter stated that by signing the paper he approves the listing of the assets, but he does not. So if he signs this is he forfeiting all rights to the rest of the trust? His uncle told us that the reason for only the bank accounts being listed was that was the only two things still in her name when she died and the rest of the assets were in the name of the trust. We are in Tennessee and he is in Ohio, so it is difficult communicating and getting straight answers.