So I have been told & seen. At the former CD/RA stations there are dispatchers usually but they do not operate CD/RA plungers. They raise the white baton & the driver checks the high quality monitors in his/her cab,shuts doors & goes, East Croydon included.
That’s really not how dispatch works on NR metals. Nor have you seen full DOO dispatch of 700s at staffed platforms anywhere south of London Bridge. You’re getting very confused between the “SATs with Bats” concept on the Tube, and modes of DOO dispatch on the wider National Rail network in scenarios where there are no safety instructions given by any platform staff.
CD/RA stations are not a “thing” - CD/RA is just the name of one approved indication method of displaying Station Work Complete and Train Safety Check Complete signals to a driver, present on certain platforms. You would not be displaying batons to any driver if CD/RA indicators were present, except under degraded working. The concept of displaying a white bat to the driver as part of a procedure also involving in-cab monitors is also not something which is in accordance with the Rule Book at any National Rail station, as in-cab monitors are for driver-only dispatch at selected approved locations.
East Croydon and many other stations south of London Bridge still retain dispatch by platform staff for 700s. There are recently-issued dispatch plans (which I have read) which will include this for the time being. Some platforms have CD/RA, some handsignal + RA, and some only have handsignals. Some of these methods vary for 700s as against other stock, but dispatch is still carried out by station staff. This may change, but not yet...