Plants vs. Zombies from 2009 and its sequel Plants vs. Zombies from 2012 were both immensely popular, and even had the highly successful spin-off Plants vs. Zombies: Garden Warfare in 2014. But after that, the momentum went out of the series.
There's no Plants vs. Zombies 3 and Plants vs. Zombies: Garden Warfare 2 was designed as a live service game without the charm of the original, which quickly ran out of steam. It was only last year that we started getting signs of life from Plants vs. Zombies 3, but apparently the reception has been very lacklustre.
Now a 3D Artist on Reddit writes that he worked on the project and shows some pictures from it via ArtStation, and reveals that it was cancelled. We don't get an explanation as to why, but spontaneously it feels like a Plants vs. Zombies 3 is something that would have fit very well into today's gaming market.
Even if PopCap Games and EA would resume the project again, it will not be released for a long time.