Correct. But notice that the S88 connection is marked "IN".
All of the 4088 devices that support a non-S88 primary connection, like the LN which uses LocoNet, reply on the S88 protocol for connecting the 2nd, 3rd, 4th, etc devices.
If you check the manual for the basic 4088 device which has no suffix you will see that it has an S88 connection marked "OUT" as well as the connection marked "IN".
If your command station needs an incoming S88 connection you need the basic 4088 device.
Frederick