Re: "These airwaves could be used immediately after release"
Virtually every high end phone sold in the UK in the last year has support for TD-LTE at least on Band 40 (2.3GHz, which is the important band) , and mostly other bands as well. So do an increasing number of mid-market phones. Quite a few phones sold between one and three years ago do have such support, but it's hard to predict which ones. TD-LTE and FD-LTE are used alongside each other in many Asian markets, and whether the phone sold here supported TD-LTE depended on whether the manufacturer was selling a different variant in Europe from Asia or not. Some were, and some weren't.
For instance, the last three generations of iPhone sold in the UK do have such support. The Samsung Galaxy S7 sold in the UK has it, but the Galaxy S6 does not. For other manufacturers it varies.
If we assume that most heavy data users have phones that are reasonably high end and/or fairly new, I think the claim is fair that TD-LTE on 2.3GHz will be used pretty heavily here the moment it is switched on.