BT announced recently that they were spending an extra £50m on infill of cities that previously missed out, or rather the few cabinets within cities that missed out. Perhaps your exchange is being evaluated for that.
And while BDUK funds might be a no-no for central Glasgow, there is also the prospect of vouchers from the connected-city fund, if you are a business. I believe Glasgow is one of the cities that has access to these funds.
[I suspect that the voucher scheme might be one of the aspects prompting BT to go back and add some cabinets - the prospect of a slight uplift in demand caused by the voucher scheme could be enough to raise viability of some cabinets.]