Before the event such proclamations are ‘facts’;
“We have no doubt whatever in regard to the chronology relating to the dates of 1874, 1914, 1918, and 1925. … There can be no more question about 1925 than there was about 1914. The fact that all the things that some looked for in 1914 did not materialize does not alter the chronology one whit.” (Watchtower, May 15, 1922, pages 147 and 150).
“in accordance with the soundest laws known to science - that we affirm that, Scripturally, scientifically, and historically, present-truth chronology is correct beyond a doubt. … Present-truth chronology is a secure basis on which the consecrated child of God may endeavor to search out things to come.” (Watchtower, June 15, 1922, page 187).
“The physical facts show beyond question of a doubt that 1914 ended the Gentile times; and as the Lord foretold, the old order is being destroyed by war, famine, pestilence, and revolution. The date 1925 is even more distinctly indicated by the Scriptures because it is fixed by the law God gave to Israel.” (Watchtower, September 1, 1922, page 262).
After the event when they have failed, they become ‘opinions’.