Casdon: "Could it mean that no evidence has been found that he was planning to flee in the first place? It’s hard to know how reliable a source told the speaker."
We can only speculate. I would imagine the Police had reasonable grounds to accept the tip off as genuine and to suspect the flight risk was possible/ probable, in order to have sufficient grounds to arrest PM and impose the bail conditions in the first place. The solicitor representing PM, was able object during period of arrest, to the bail conditions by way of providing evidence and submissions why they were not necessary and/or disproportionate. They are renowned to be one of the best firms in the business. Seemingly they were not successful at the time of arrest...
Either PM or his solicitors may have since provided further submissions and/or evidence sufficient to mitigate the flight risk in order to have them lifted. Or the police decided on reflection (PM's solicitors were vociferous and aggressive in the press statement they made about the bail conditions) no doubt to put the police on the defensive, that the flight risk not sufficient to warrant the press scrutiny.
The police are highly unlikely to provide details as to reasons and PM's lawyers just capitalising on them being lifted.