NJ
I believe they were moved from ITV to Channel 4 in May 1983 to co-coincide with TV-am getting the slot until 9:25am, and also having updated the network to allow automatic switching, as opposed to the manual switching job they had to do before (IIRC TV-am was due to launch after the upgrade work, but they wanted to get going sooner thanks to the BBC launching their programme in January so TV-am had to be bodged in to the system as it were).
Yes, the final IBA announcements on ITV were in May 1983 as far as I'm aware, when TV-am was extended from 9:15 to 9:25.
I believe they were moved from ITV to Channel 4 in May 1983 to co-coincide with TV-am getting the slot until 9:25am, and also having updated the network to allow automatic switching, as opposed to the manual switching job they had to do before (IIRC TV-am was due to launch after the upgrade work, but they wanted to get going sooner thanks to the BBC launching their programme in January so TV-am had to be bodged in to the system as it were).