What a complete load of bull.
You buy a ticket at point A and go to point B with a start time.
You use your card and start at point A and go to point B with a start and end time.
They already have all this information. You can quite easily combine the above with train and tube times to work out the route take.
This is neither necessary or useful, in fact I would say it would confuse things because of the strength of WiFi signal and whether the device gets registered at each point.
Now if I put my patented tin foil sailors hat on I would surmise that this along with free WiFi on busses is another way for the guberment to track people and where they go before they enact the 1984 protocols and enslave mankind to a bleak totalitarian future where everywhere you go and everything you see is recorded and analysed for purposes of submission to our lizard overlords. You have been warned citizen.