In terms of what the company was going to do (or has done) with the London facility and cleanroom, this is the difference between what they wrote in the last SEC filing in August:
The Company and Advent undertook strategic planning for consolidation of the operations in the London GMP facility and the Sawston GMP facility, to reduce overall costs and increase capacity in Sawston.
...and what they wrote in today's PR on the Advent acquisition and what it would allow them to do:
Closing of operations at the GMP facility in London and reallocation of resources to the Sawston, UK facility and to capacity development in the US;
So why are they connecting the US "capacity development" to the closing of the London facility? They could just be explaining how closing the tiny facility at Kings Hospital (I think) allows them to allocate more money toward US capacity build-out. Or, they could be quietly directing our attention to the fact that US buildout is happening, or is imminent. Even as they're NOT talking about an MAA approval that MIGHT be happening in the UK.