I find it interesting that there have been accessories for the 850 advertised. So far I've seen reports of a case and a tempered glass screen protector.
I can't post links but the case is for sale in brick and mortar stores in Germany and Amazon Italy has someone selling tempered glass screen protectors “designed for Microsoft Lumia 850 ONLY." Google it...
It may be that these will actually be for the 650 XL, but it makes you wonder.