This request is to make MS TEAMS works exactly in the same way as JIRA UI. Because nowadays, if you click on CREATE missing some required fields, JIRA will display a message at the top showing you which fields need to be fulfilled.
If the JIRA instance has required custom fields that are not supported by MS TEAMS (example: Scripted fields by ScriptRunner), those fields will not be displayed on MS TEAMS.
Therefore, from the MS TEAMS user perspective, all the required fields are being fulfilled, however, that's not the truth, because the custom fields which were not rendered will prevent the CREATE Button to be clickable.
If we display the list of required fields anywhere (like near the Create button), we will show to the users which custom field is preventing them from creating the ticket.