It'll be interesting to see if this represents a change of mind set. I can understand why TfL wanted to protect the Piccadilly line from overcrowding, particularly in the central sections but, as the new stock comes online, the extra capacity reduces that risk.
The next test will be if they become more amenable to temporarily stopping at Turnham Green during District line delays when the platform is getting overcrowded.
If so this may herald a gradual upgrade of the service ahead of the full introduction some time in the distant future.
Andrew OSullivan ● 5d