It's clear to me now that the rNWT capitalizes several words that were previously not capitalized in the NWT, and this is why they are capitalized in the Teach book too (another example is that "heavenly kingdom" is now "heavenly Kingdom").
An amusing error on page 71 was fixed. "Countless trillions of stars fill the universe, yet God gives the name of each one! (Isaiah 40:26)". That must be a long Bible verse! In the new edition of the book, "gives" was changed to "knows".
On the same page, "Jehovah actually yearns to bring the dead back to life" now reads, "Jehovah longs for the time when he will bring the dead back to life". Not sure what the intent was in this change.
A remark explaining what Hades is, on page 72, was removed since the quoted scripture now says "the Grave".
On the same page, "we may be freed from any dread of dying" was changed to "we do not have to be afraid of dying", an editorial improvement.
On page 74, a sentence about Jesus' resurrection was split into two sentences so that the scriptural backup could be placed after the statement it actually serves, not the unsupported statement that follows.
An amusing change on page 78: "Would you want to have a ruler like that?" is now "Would you not want to have a ruler like that?" to make the intent of the question clearer.
On page 82, "the battle of Har-Magedon, or Armageddon" now reads "the war of Armageddon".
The next sentence, "What will God's Kingdom achieve by means of Armageddon?" now reads "What will God's Kingdom achieve by means of the war of Armageddon?" This is probably because Armageddon is a place, not an event.
Doctrinal statements not changed include the heavenly calling still being open, and remarks about 1914.
It seems that the minimum justification (word spacing) in the book was raised, so that some lines are less cramped than they used to be.