Could the M365 outage be affecting the Windows Media Creation Tool?

The same error was reported in both North America and Europe, including with a previously downloaded copy of the tool. That makes a broader service issue plausible, though it doesn't prove the M365 disruption caused it.

The original issue was later reported as resolved, so trying the tool again may be worthwhile.

If you can download the Windows ISO directly, you could use Rufus to put it on a bootable USB drive instead. That worked around the tool error in one report, but the ISO download also failed for someone else during the disruption.

There were also reports of Windows Update errors and trouble enabling optional Windows features around the same time. Those are useful things to check if you're troubleshooting, but similar timing alone doesn't establish a common cause.