If this is code for something, then three different possibilities come to my mind, ranging from boring to disastrous:

• There's a now-deprecated Twitter feature called "Moments", which went read-only some time ago. Maybe it's finally being killed off completely. Ho hum.

• The movie quote refers to a dying artificial human character, so maybe Twitter is gearing up for another mass bot purge. Might be fun.

• Taking a more wild guess, could "rain" refer to Internet cloud server infrastructure? Clouds turn into raindrops and disappear; is there going to be an Internet blackout that results in catastrophic levels of data loss?

Or maybe Elon's just trolling for the fun of it. Heck, I'd do the same if I owned Twitter.