The above reference correctly states:
"The presence of an electrolyte and an electrical conducting path between the metals is essential for galvanic corrosion to occur."
An electrolyte is generally considered a solution (e.g. water, with ions).
Unless you store metal climbing gear in a moist condition, for a very, very long time, I can't see this as a real concern.
Plumbing systems erroneously assembled with dis-similar metals last for months or years in continuous contact.
Steel & aluminum are obviously different hardness's.
If the forces are high enough, deformation of the Al will occur.
My guess is that if it were Aluminum-to-Aluminum (same alloys & geometry) the deformation would be pretty equally distributed between the two.
Just inspect your gear & be observant.
