The Island Line's Class 483 EMUs are about to end their service, and they will be replaced with the Vivarail D-Train Class 484 (built by Vivarail). The Vivarail D-Train is a battery powered electric multiple rebuilt from the bodyshell of old London Underground D-Stock trains. It has 2 variants - the Class 230, used by West Midlands Trains & Transport for Wales, and the third rail powered Class 484 for the Island Line. A Vivarail D-Train Class 484 for the Island Line Image Source: Vivarail
This train can't be added since the time period that the isle of wright is in. It's way before these trains entered service so unless a "modern day" version is made, this train will not come. Sorry
I wouldn't discount Class 484s, but yeah, there'll probably have to be a modern version of the IOW route with them. Since the D-Trains are derived from sub-surface stock, they're considerably taller than the preceding Class 483s, and so some of the upgrade works currently taking place on the Island Line include modifying the platform heights to match the doors. The current Island Line route is configured for the deep level stock 483s, and thus has shallow platforms that would be quite some way below the door sills of the 484.
This is a lot like gwr , lots of people have requested the class 800 but we will not be getting it as it is not operational during the time period in which the route is set . The same applies for the iow line , because it is set before the 484’s were in operation on this line so I find it unlikely that we will get this loco