How may I change file ownership of an XD file?

Hi there, I work for a large organisation which is using XD across 34 projects which means hundreds of XD files. We have a couple of members of staff who leaving and are the majority owners of the work.

We have added the other team members but we have them as the owners and are worried when they leave and their licence removed we will lose these files?

I have looked online for some help and documentation and only found a couple of poor articles which would lead me to worry this isn't an option. I have seen some community questions asking for this? So.. is there any update on this at all?  I have seen the same copy and paste reply on several message boards around this issue all of which say that the engineering team is working actively on a solution but that was 18 months ago. is there any news on this, I am struggling to understand how this isn't an item to be prioritised.