I believe new games like this actually increase the overall general interest in Pinball and increase the value of older games.

New people are coming into Pinball as a result of these new titles. Themes like Star Wars, Teanage Mutand Ninja Turtles, Rick and Morty and surely Guns and Roses become gateway pins that cross people over from other genres and they wind up buying a pin because they are interested in the theme.
Next thing you know, one pin turns into two. Two pins turn into three and so on.
This drives up the price of classic pins as new blood comes into the hobby. Unlike modern pins, the survival rate on older classic pins in no where near as high and there is a finite supply. Hence prices go when there is more demand than supply to meet it.
As prices continue to rise on NIB pins, older pins that can be had much cheaper than NIB items look pretty darn desirable from a monetary standpoint.

Precisely.
A rising tide lifts all boats.

100% this.
The housing market is a perfect example.
The buying power of money is not what it once was.