they arent going to lose next gen if they do.
They PS4 will just become cheaper and act as the entry level model into the ecosystem. PS5 will have BC with PS4, and Sony's AAA budget games will move to PS5 while the AA budget and digital titles remain come to PS4 for a year or 2 (alongside MLB).
PS4 dropping in price will allow it to continue selling for a good few years (something the PS3 couldnt do because it was just too difficult to drop the price, ad because PS4 was doing so well that it was better just to phase the PS3 out) to lower income brackets and 2nd console buyers.
if they release PS5 any later than XBOX NEXT then they will have a problem,not a big one but Microsoft have alot of money to make that their advantage
if they want to drop the price of PS4,it should happen this or next year