I just checked and this CPU2 meter appears on the screen when editing delay and reverb blocks, when you approach 80%.
With all 4 of those blocks in the grid and the ultra-high quality capricorn type selected in both reverb blocks cpu2 was at 79.8, as soon as I deleted a delay block it went down to 72.8.
So they definitely run on the same core.
PS: if I select the diffused delay on both blocks cpu2 goes up to 89% but still works fine (fm9 turbo here)