Does Mac support thumbnail preview when clicking on the file in finder?
Not currently, but it is being worked on. No estimate for release, but work has started. 
Hi Rikke, is there anything new in the development of this?
I do not believe there has been, but let me check. 
Update: I was incorrect when I reported, “…work has started.”.
We have an internal task set, but it remains lower on the priority list.