yea i'm fairly certain activation lock would prevent the phones from working, one interesting fact is that they can disable accessories based off the serial num

yea i'm fairly certain activation lock would prevent the phones from working, one interesting fact is that they can disable accessories based off the serial number, iphones won't connect to an accessory if apple identifies it as banned which is the meaning behind those "accessory not compatible" messages. this happened a while back when apple bricked all those 2-in-1 lightning passthrough + headphone jack adapters overnight with a software update, but even if they could i doubt they'd do it to their own cables.