Anna Marina, they've already taken steps to change this teaching. The Watchtower has a habit of slowly introducing new ideas before committing to a completely different doctrine.
When they released their latest Bible they included a timeline and in this they mention the year 1914. Of particular note, they do not mention Jesus' presence and instead they only include this statement
About 1914 C.E.
Jesus hurls the serpent, Satan, to the earth, confining him there for a short time.—Revelation 12:7-9, 12.
https://wol.jw.org/en/wol/d/r1/lp-e/1001061221
They use the word 'about' when mentioning the year 1914 as the time Satan was hurled to earth. Stating that this occurred about 1914 means that they are no longer confident or even teaching that he was hurled down in 1914 as definite year. What they are planning in new doctrine is anyones guess but they have laid the groundwork for it.