FYI, I asked WMF Communication Team about any plans of using Mastodon in future. 

Here is their response [1] "The Digital Communications team has been researching Mastodon and considering our potential involvement with the platform in the future. At this time, we have no plans to create an account for the Foundation or Wikipedia. This is mainly because our observations show us that Mastodon is not yet reaching a large audience, which is one of the key objectives of our communications activity on social media. We will continue to monitor the situation and adjust our recommendations and practices to keep within our objectives."