Not all cabinets on an exchange get upgraded and new build are frequently not done maybe because they are uneconomic. If the chat operator has checked then they have access to up to date info. I and others on the forum can only access "leaked" info the most recent was early December and does not show your postcode as planned but we are nearly 2 months on now.
If you are going to get Infinity a couple of months before new "fibre" cabinets will start to be installed close to each existing cabinet keep an eye out for Openreach trucks etc. BT are coming back to many areas to do more cabinets so it looks hopeful.
Cabinets contain room for hundreds of lines in my area it took 10 years to fill ours as new estates were developed in the area so your estate alone may not be enough. In any case BT never talk about how they choose which cabinets to do so we are just speculating.
The build of the estate was complete around 2006/07, and every property on the estate is settled so I would imagine all my neighbours are waiting for infinity also, doesn't that count as economical?
Get all your neighbours and local businesses to register their interest for Infinity. Pester your Local Councillors and MP's to put pressure on BT to include it in a future round of upgrades.