In Jira Server/Data Center, whenever an issue key is added into a comment, there is an automatic link to the issue as well as a visual confirmation of whether the issue has a resolution set or not by getting a strikethrough style, like this:

In Jira Cloud, since there is a different system for rendering URLs, this does not happen, even though adding an issue key is recognized as one and we can see the issue key represented in 4 different ways, the formatting style "URL" or "Inline" do not give an indication of whether the issue is resolved or not, requiring the user to open the link just to know if the issue is resolved:

• Inline style shows the status, but not if it has a resolution.

The suggestion is to incorporate the automated Strikethrough style over the issue key whenever it is displayed in URL or Inline styles.

• Since the URL style is a free text, it is understood that it would be possible for the users to edit the Display text if they want to, but adding the Strikethrough style over the default URL rendered would still work.