I'd say this one's minor. It's an irritation. I only found it when posting pieces of a query's XML plan.

Though do note that it happens in other code markups than XML, which can be a pain as I and some others use < and > to indicate a placeholder in code.

As such:

DBCC CHECKDB () WITH NO_INFOMSGS, ALL_ERRORMSGS

That should have been

DBCC CHECKDB (< Database Name > ) WITH NO_INFOMSGS, ALL_ERRORMSGS

Code blocks other than XML shouldn't be trying to close tags at all.

Hmmm, add another bug. Automatic adding of ="" on what's not intended as an xml attribute. This kind of 'validating' should only happen on code blocks with an xml-related description, not on SQL ones.