I had the same problem yesterday and this morning. I tried again this afternoon and 2 Content Types Published OK. Then I got the error again on the 3rd and 4th etc...
This from the Office 365 Admin's Advisory Panel
SP98120 - Content type publishing issue
Updated: 2017-04-07 21:51 (UTC)
Start time: 2017-04-05 19:14 (UTC)
Status: Restoring service
User impact: Users are receiving errors when publishing new site content types from the SharePoint Online content type hub.
Latest message:
Title: Content type publishing issue
User Impact: Users are receiving errors when publishing new site content types from the SharePoint Online content type hub.
More info: The error received says: "The operation failed on one or more Metadata web service application proxies: Taxonomy_masR1gLITCWWPDUbODEIOA==. Please contact your administrator and check the log files for more error details...
Correlation ID: 2d75e59d-90d6-3000-f0d6-00d2f9b3649e"
Current status: We've confirmed our suspicion that the cause of impact is a permissions configuration issue. We're not certain how this issue was introduced, but we're working to develop and test a fix that should resolve the underlying cause. We expect the fix to be ready for deployment within the next 2-3 days. In parallel, we're continuing to investigate how this issue was introduced.
Scope of impact: A few customers have reported this issue, and our analysis indicates that this issue may potentially affect any of your users attempting to publish new content types.
Start time: Wednesday, April 5, 2017, at 7:14 PM UTC
Preliminary root cause: A critical file within the systems that facilitate publishing of site content types was inaccessible due to mis-configured permissions settings. This resulted in intermittent errors when users attempt to publish new site content types.
Next update by: Monday, April 10, 2017, at 6:00 PM UTC