Basic development and scenario production have already been completed for Final Fantasy XVI, according to a recent job posting on a Square Enix recruitment page.

From the Square Enix Final Fantasy XVI recruitment post:

Basic development and scenario production have already been completed, and we are continuing to create large-scale resources and build boss battles while expanding various development tools. In addition, most staff work remotely.

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(Environment production, cutscene production assistants, animators, VFX, etc. are being recruited with particular emphasis)

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In particular, we are looking for the final staff to create the world of FF16 together with us, such as creating various stages / fields, large-scale cutscenes, and creating character actions.

Final Fantasy XVI was announced for Playstation 5 on September 16th, 2020.

Square Enix has launched a teaser website.