I've just come across the PIN, which gives more detail to prospective contractors and appears to confirm the details of the meeting - seems TPWS (and cab radio!) really are on the cards: http://bidstats.uk/tenders/2019/W39/711590030
Track works: A number of interventions are planned along the extent of the Island line to accommodate the new trains and improve track ride quality. These interventions will be items such as rail replacement, closure of current jointed track, ballast replacement, tamping, track lowering at stations and minor gauging interventions. A new passing loop will be provided at brading station and platform 2 will be reopened for passenger use.
Civil engineering works: Civil engineering works will be carried out at the current station sites to complement track lowering and where this is not possible, the application of a new surface to the platforms to raise the platform height. There are a number of structures that require intervention such as minor bridge decking works and retaining structures.
Signalling works: New signalling will be provided to control the new loop at Brading station together with the provision of a new control panel at Ryde St Johns signal box. Additionally, TPWS will be provided throughout the Island line together with the upgrading of a number of point mechanisms. To support the new signalling system at Brading station, a time division multiplexor system will be installed which will also replace the current westinghouse S2 legacy system provided at Sandown.
Telecommunications works: A cots ethernet compatible fibre optic transmission system will be established on the Island Line to support the new signalling equipment and train radio system. This system will be compatible with VOIP systems.
Electrical supply works: A number of station power supplies may need upgrading as part of the works to support the new signalling and systems which will require co-ordination with local DNO operators.