Whether a Bug can be linked with a TestCase?

No the bug should be never linked with the TestCase as far as Azure DevOps is concerned as the TestCase can be present in multiple suites and the TestCase can be used in different releases, so general practice is not to link bugs with the TestCase, instead the bugs are linked with the user stories and requirements

When bugs are linked with Requirements, its helps us to track quality of development as we can see how many bugs are linked to a specific requirement.

So the general rule is Bugs should be never linked directly with the TestCase and it should be linked only with the Requirement (The bugs created from the TestRunner are not linked with the testcases but with Requirements directly)