Juneteenth is a legal holiday in Texas, since 1980, say all the web sites I've checked, although it was several times proclaimed for a particular year before that.
Almost everything I've ever read on the history of Juneteenth expresses shock and dismay that the slaves hadn't been told they were free years earlier. Yes, it sucks that the slaves weren't freed earlier, but people who write this way are fairly uninformed about the Emancipation Proclamation and the relationship of the Confederacy to the United States. Abraham Lincoln's proclamation specifically said the slaves were free only in those states that had left the Union (not the couple of slave states who did not secede) -- he was basically giving an order covering only the territory he had no authority over (by the view of the government controlling that territory). In most places, slaves did not learn they were officially free until Union soldiers took over the area they were in, or indeed until the American Civil War actually ended in April 1865. (Sometimes after the war ended, as in this case of Galveston, where the U.S. troops didn't get there to occupy the area until June 1865.) The slaveowners were not about to give up the free labor until someone made them.