Because of Crypton's announcement a couple days ago, I thought it would be fun to resurrect this thread and see which predictions ended up being right (or at least pretty close). (I know there are still a few months left in the year, but I'm too impatient to wait for the true end of the year.)
Failed predictions:
The 1st Vocaloid to get updated to V5 will be a new face > Didn't even happen, might never happen now...
Next company to join Vocaloid will be a new face > Same as above...
New UTAU developments
Bilingual Vocaloid
Gumi V5 (or any other Vocaloid getting updated to V5)
CeVIO: A Chinese voice and an update + new companies join
Korean Synth V
Any suggested new language for Synth V other than Chinese, Japanese, and English
New Voiceroid guy
Synth V explodes in popularity
Spookily accurate predictions:
Emvoice is released (does beta count?)
No new companies join Vocaloid, companies go to other engines > We're looking at Quadimension with Synth V and Crypton!
Zing never released > I almost forgot about her
Mirai Komachi gets a 2nd song and continues activities > She's not dead yet
Unity-chan resurrected because of VTuber activities > but then died again
CeVIO will demo their new deep-learning-based engine, but won't be ready to sell it this year (pats myself on the back for this one)
There will be another Vocaloid/Voiceroid combo > Haruno Sora
Yamaha hits us with another port update > The Cybers and VYs for V5
Crypton will update Piapro in response to V5
Crypton makes its own engine, splits with Sega for concerts
More Synth Vloids released than Vocaloids this year > Synth V = 3 (Chiyu, Shian, Cangqiong) vs Vocaloid = 2 (Hime and Mikoto Meika)
(These weren't all the predictions, just some off the easier to re-summarize.)