Public information is limited to once the cabinet is actually enabled, which is unlike with VDSL (FTTC) deployments. No estimated dates are available to us and I can't see this changing soon.
I presume that witchunt meant that Bracknell is a good G.fast candidate, i.e. urban, dense, premises close proximity to existing PCPs; essentially a good portion of premises would be able to eligible receive over 100 Mbps (ultrafast) as most would fall under ~350 meters (the max. range of current G.fast deployments).
You should confirm the following to us (what MrSaffron said):
If the pod, has some vents in its door then a gfast pod, if not then just a capacity extension
If the pod has no vents, then it is not being enabled for G.fast since copper capacity extensions do not have ventilation.
Your best bet is to keep an eye on the BTW DSL checker
since it will appear there once it is available on the wholesale providing your line is short enough and therefore capable of providing you the service. The Openreach Fibre Broadband checker
would be able to tell you as soon as the cabinet is enabled, but not ready for orders from the wholesale side (BTW DSL checker does that).