Yes, and given Anglo-American penetration of German codes and such, its not inconceivable that Philby would soon have been exposed that way as well.
Only question is, do the British arrest him, arrange a nasty 'accident' or attempt to turn him as a double agent?
In my estimation, turning him would not work. Philby wasn't a garden variety paid spy, he was a committed believer in the Soviet system. So I would expect him to find a way to alert the Soviets and plan an escape.
Having him and his compatriots out of their positions would save Volkov and probably any number of Soviets who worked for the UK and US after the war.