I dont see the story as being complete as it stands.
If thats where they choose to leave it then so be it, but I would prefer them to complete the story, as in work out a proper resolution for both V and Johnny.
For that to work there needs to be a way to take each of the current endings forwards, apart from the suicide ending obviously. At minimum that means two entry paths to the DLC, Johnny alive, presumably looking for a suitable body for V, or V alive looking for a cure for themselves and presumably a suitable body for Johnny.
The most logical ending to the current campaign really seems to be Johnny alive and V trapped beyond the blackwall, since that removes some of the time pressure, but I dont think CD Projekt Red can afford to just go down the one route given the star ending seems to be quite popular too.
The problem then becomes not so much finding a body, (lots of people die or near die every die in night city,) the problem is finding one that V can use. Having said that, if the relic worked once then building a second relic with V's engram on it, and inserting that into a brain dead person would seem like a workable plan. Gives the player things to collect, people with the right skills or equipment to find etc and finally a way to make it all happen, although I suspect that Vik would help there. We know V had all the information about the relic, so it should be feasible to make it again, eventually. It would also give the player the chance to go through the character creation process again if they wanted to since the new body wouldnt be the same as the original V.
I would also expect a second DLC after the current campaign end, specifically one that continues the Jefferson Peralez and Sandra Dorsett storylines.
I think a more open ended version of the game may well be possible, but I would expect that to be Cyberpunk 2078. In other words after theyve fixed 2077 as much as possible and done the DLC, so not for a few years yet.