Yes that's what i explain above. That yellow dot tells you, that you hoower over the name text field of a LFO modulator in the modulation line, as the LFOs is represented by yellow dots like that, and that that modulator is modulating something in that section (in the case your image show in FX: BUS A).
It's not only the FX buses that get a dot.
I don't know if the dots appear doing something else.