It is not missing, though RL wrote:
Launching raster assets to your PSD Editor is working exactly as it did in CTA4. Launching SVG assets to a compatible SVG editor is coming in a future update.
Please Note: Most of the embedded raster content from CTA4 has been updated to SVG in CTA5 which is why it can't be sent to your PSD Editor.
See this thread for more details:
https://forum.reallusion.com/526733/CA5-No-more-modification-of-CA-characters-in-external-editors