I (CSS - UK) am one of those who’re impacted during the previous big wave.
I received a 1-1 call (business update) invitation from my manager on 27 April, had a call to be notified that I’m at risk of redundancy on 28 April, and were on a garden leave until 31 May.
If it’ll follow the same pattern (one month after the US), the next UK round might be in mid-October.
However, some people that I know were let go outside that wave since then until now too. So it might not hit as a big wave but randomly by LoB.