Doesn't work.
If you install the older app version, it will not have any of your previous devices at all listed - you first need to add them, in order to remove them (which defeats the purpose anyway).
And as this thread is about being unable to remove old devices no longer owned by the user, then clearly we cannot first add these old devices, as we do not have them any more.
Conversely, as soon as you update the app to the newest version, all of the old devices appear back in the list anyway.