I've seen this £1.5bn loan mentioned a number of times but when I reviewed Chelsea's financials it isn't presented as a loan but is presented as equity instead. So whilst it may have started its life as a loan it has has been converted to equity over the years meaning that any buyer won't be inheriting the loan but will instead be purchasing the equity. So I don't think it'll put any buyers off or change anything they didn't already know.
I still think the bigger issue will be whether they club can actually be sold. The logistics of the sale will be very complex and require Roman, the UK government and buyer to be wholly aligned on a unanimous solution. This will be challenging and take a significant amount of time to resolve. Whether Chelsea survive this and come out the same club they are today when the dust settles remains to be seen but I am inclined to believe that troubles lie ahead.