3. The only requirement for A.A. membership is a desire to stop drinking.
The third tradition only spells out who can be a member of AA, now taking that to an extreme if a non-alcoholic had a desire to not drink even if it was just for that day, they could be a member and share.
That is taking it to an extreme, as Sugah says, a group conscience can decide that "all are welcome, but please, only alcoholics share."