While that would be a sweet deal, I would not expect an entirely free unit as compensation for kickstarter reward delay no matter how long. (even as a loaner, they loose that "new" unit).
What are they supposed to do just eat all the new units revenues ? and still give you another one too. I think it would be more likely to get your order changed to the 8k Instead of the 8kx if you do not want to wait, or speak to them about a refund option. I just cannot see them sending out fresh clean 8k units as loaners. Would be sweet for you 8kX guys/gals but.. I would be surprised, very surprised if they allowed that.