I haven't seen any official statement concerning restoring this capability.
If you want to try this out, change the bit depth of one of your image to 32 bit in Photoshop and go to Filter/Camera Raw Filter and you it see it is greyed out. The workaround does not work. I am trying to use the merge to HDR pro version which creates a 32 bit whitepoint file. The reason that I used the HDR conversion version which uses a 32 bit file is because that version lets you decide which frame you use to Remove Ghosting and that is better for moving water images in my opinion
Can you please follow my Tutorial 16 on my website and see if it works for you?
I normally select 5 bracketed DNG images in Adobe Bridge then go to Tools/Photoshop/Merge to HDR pro.
I then select 32 bit mode and tick the Remove Ghosts box. I then click the Tone in ACR button and it should merge the files in ACR but I get the warning, The Command "Camera Raw Filter" is not currently available . I have just tried it again but it still will not work.
I am using Windows 10 Pro system with ACR 9.12.1
Method 5: Use recommended settings for Photoshop's Merge To HDR Pro feature
When using Photoshop's Merge to HDR Pro feature, we recommend that you use either the 8-bit or 16-bit mode (with Photoshop's built-in tone mapping options), or 32-bit mode with Complete Toning In Adobe Camera Raw deselected. You might encounter issues with the Complete Toning In Adobe Camera Raw workflow at the moment. Adobe is considering fixing this workflow in a future Photoshop release.What works for me is to NOT check 'Complete Toning In Adobe Camera Raw' and then save the resulting 32bit PS document to TIFF file format. You can now open that TIFF file in ACR with no issues. Does that work for you?
But when I tried to open the 32 bit file in ACR the Filter/Camera Raw Filter is still greyed out.
The problem seems to be that I cannot get ACR to accept any 32 bit files.
Anyhow, you need to think out-of-the-box to get it to work NOW. Mind you I rarely use PS/ACR for HDRs, but give this a try. After you save the 32bit TIFF file, close it, and open it from Bridge with right-click 'Open in Camera Raw. After applying Toning in ACR hit the 'Save' button to write the settings to XMP metadata in the TIFF file. Now every time you open the file in PS it will automatically open in ACR...at least it does for me!
CORRECTION: You need to have the following Camera Raw Preference selected for the 32bit HDR TIFF file with toning settings to open in ACR automatically:
If I now go to Tools/Photposhop/Merge to HDR in bridge and select the 32 bit floating white point option without ticking the Complete toning in Adobe Camera Raw. I then save the file as a tiff instead of a .psd file. I can then right click on the Tiff file and select "Open in Camera Raw" where I can complete the toning. (Saving the file as a PSD file does not give me the "Open in Camera Raw" option)
You have now helped me to effect a workaround with the same outcome as I am used to which allows me to choose the frame that I want for Ghosting removal. This is important when doing HDR images of moving water as I can then mostly choose the frame in which I like the effect of the water flow. (This doesn't always work but in the main it does.)
When I have completed the toning, I can now output the file from ACR into photoshop as a PSD smart object.
Many Thanks Todd