Not possible. To create automation, something other than watching issues needs to be triggered, such as issue transition, issue creation, modification or etc.
I've checked to see if watch issue is considered issue update, but that seems no. So no, this is not possible. But with an add on, this is possible. There's an add on called Autowatch for JIRA that can help you auto watch an issue based on criteria or JQL. So you can have something like
JQL - reporter in (list of the users in the team)
Users - The watcher
Hello, Atlassian Community! I thought it would be fun to do something different for my teams' last retrospective of 2019 so I'm planning to do a "year in review" with info-graphics. Wha...
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