I'll ditto François, I think if you use DNG converter, you should be able to convert newer raw files to open within older versions of Photoshop. I used this workflow and raw+jpeg a few years ago to open my files while I awaited a Photoshop upgrade.
Today, there doesn't seem to be quite that time lag between a new raw format and an update to ACR/Lightroom to handle the new "flavor".
The software for DNG converter is free for the downloading and worth a try.