You could conceivably replace most of an ElectroMechanical machine's steppers and relays and score reels and things with a microcontroller and digital displays, and there are transitional machines that were factory produced as EM and Solid State, but I think you loose the character of the games that way. The buzzing and thunks and the lamps turning off while it computes and all that is part of the experience.
If there's no way to make the games work as they did originally, sure, make them work again by any means, but while we can make them work like they did, we should.
There's p-roc and p3-roc that offer the basics of a computer to pinball interface board (you'll need at least a solenoid driver board, too). That would probably be the basis of control for a modern enthusiast built pinball machine. Most enthusiasts are trying to build something that fits more in the Solid State era than the EM era though.