Just don't buy the new one thinking it has anything to do with the previous Black Mirror games. The only thing it has in common is the game's title and that the name of the family is "Gordon." The story is not a continuation or a prequel -- it's a completely disconnected story -- a "reboot."
It is not a "Black Mirror 4."
The point-and-click gameplay is gone too. So unless you enjoy console ports, you may want to wait and not pre-order.
Expect the new one to have plenty of QTE's and other dexterity-dependent "challenges" for the console gamers -- moreso than in Syberia 3. So if you're not good at these, you may have to ask for a lot of saved games -- and there may not be any available.
On the other hand, if you haven't played Black Mirror 3 yet, enjoy that one, which picks up where Black Mirror 2 left off.