Transferring 1000 miles from BA to Iberia doesn't count as new activity. The date on which the last Avios-earning transaction occurred is the starting point that determines when your balance (including that 1,000K from Jun-30-2019) will be zeroed out.
It's worth pointing out that transferring Avios from BA to an IB account that hasn't had had any recent activity can result in the new Avios balance being suddenly wiped out during a random sweep by IB's systems. Personally whenever I want to book an Avios award in my dormant IB account with Avios from my BAEC account I will only make an Avios transfer from BAEC a few minutes before booking the IB award.
Last edited by London Dude; Nov 3, 2021 at 7:58 am