Yes, those are the supervisory chips that are used to communicate with the I/O sections of the board and make a working game.
BUT, those chips are not the complete end all solution to every game system. Some game software requires their own specific 4 chips to work.
They are the most popular set of 4 chips that are used, I agree, I use them also, but in my years of repairing S5500 boards have I found game software that will not work with that specific set.
Don't call them "leave in mains", call them "the most popular and latest supervisory chips that work on most game systems and allow clearing the memory by using the SRAM jumper".