Well, before the new Atos system came in, there were announcements on the platform.
Some bright spark at FCC decided to configure the new system so you get an 'on approach' announcement and nothing else. Not even announcements in advance, for the benefit of the partially sighted, unless there's a delay. FCC (and/or Network Rail) also decided that Hatfield should no longer be zoned as it once was, so you can be told to stand clear of platform edges while in the station building.
Before that, when a 313 arrived at New Southgate you'd hear (more so if the doors were opened) 'New Southgate. This is New Southgate. The train ....'
Perhaps GTR could consider reinstating this? Could be a temporary fix until the new rolling stock arrives?
Do GTR have those online forums like FCC did?