When trying to locate a copy of the document, I ran across the following excerpt from the "abdication" papers Michael signed:
"A heavy burden had been laid upon me by the will of my brother, who in a time of unexampled strife and popular tumult has transferred to me the imperial throne of Russia. Sharing with the people the thought that the good of the country should stand before everything else, I have firmly decided that I will accept power only if that is the will of our great people, who must by universal suffrage elect their representatives to the Constituent Assembly, in order to determine the form of government and draw up new fundamental laws for Russia. Therefore, calling for the blessing of God, I ask all citizens of Russia to obey the Provisional Government, which has arisen and has been endowed with full authority on the initiative of the Imperial Duma, until such time as the Constituent Assembly, called at the earliest possible date and elected on the basis of universal, direct, equal, and secret suffrage, shall by its decision as to the form of government give expression to the will of the people."
I agree with the blogger that Michael neither accepted or disavowed the throne but instead said it was up to the Russian people to decide what form of government they wanted. In other words, he would rule as a constitutional monarch if that is what the people wanted.