I don't think so.
I have enough experience with LR to know what to expect for various activities.
Previews for all photos had been rendered long before I initiated the Save Metadata.
Metadata for 50 of the 52 files had already been written.
The high cpu had gone on for at least 5 minutes. I switched to another app imediately after initiating the Save Metadata for the 52 files and only went back to LR when I heard my CPU fan running for a long time.
When I got back to LR, I saw the "Could not save metadata" window. I clicked "Show in Library" and OK. As soon as I did that, CPU usage went back to normal.
I've experienced the exact same scenario, where LR can't save metadata for all photos and I've never had LR get stuck consuming a very large amount of CPU.
As a test, I selected 118 other photos, changed metadata for all of them and then selected all and saved metadata. LR took about 20 seconds to save metadata for all 118 and LR CPU usage never went above 17%. The difference is that LR did not show the "Could not save metadata" window.