No. Jira only allows one assignee at a time.
I understand why - where systems do allow for multiple assignees, you often find everyone says "not my problem, one of the others should be handling it" and nothing gets done, but equally, multiple assignees is very useful.
I usually work around it by using one (or both, or variations on):
Hey Community mates! Claire here from the Software Product Marketing team. We all know software development changes rapidly, and it's often tough to keep up. But from our research, we've found the h...
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