Reasons for her publicly going on about 6 months now might include the press repeatedly asking questions about the timescale, despite the obvious answer that they dont know until they evaluate what effect the measures have on the data, and what effect that data has on the modelling.
Sections of the press already soiled themselves in the process of looking for any news, reports, models which could possibly indicate a nice quick exit from this situation. Under those conditions, I too would be forced to go on about some rather long timescales in order to compensate for that.
It also likely reflects the Imperial College suppression idea where all measures dont necessarily stay in place for the entire duration of the main Covid-19 threat, they might turn them on and off over time based on certain indicators such as level of intensive care admissions.
I am not going to freak out about this aspect of the statements made today. Large amounts of the focus has been on testing of various sorts in recent days, that stuff is clearly part of the plan now. It will take them time to get their shit together on that front, and what they plan to do with the tests may still fall well short of the all-out suppression & testing & comtact tracing approach, but we wont really know that until an actual opportunity to try that stuff arises again, and I think the government know that too. So it just goes into the large pile of issues that are in a state of suspended animation for me. Because I cant take them much further until we have seen the terrible data on hospitalisations and deaths from the first wave, and when and to what extent the lockdown makes a difference. Combine that with a few other things we might learn about the epidemic such as via testing to determine what order of magnitude of people were mild/asymptomatic cases, and it will be much easier to say exactly what the next