That does not make sense, unless Antoine ran out of email addresses;-)
Since there's always HashTags like #Java_Social, the account is not incredibly important. I chose to not delete jsr357 as it serves very little purpose outside the JCP, but let's say for some experiments where you don't want all your friends and followers to be affected, I felt, an account like that may serve well as "dummy" at some point.
The important thing is, that except for "Samoogam" I believe none of the other names is available as Twitter name, so we'd be forced to use some variations let's say @Bacino_Social or @Agorava_Social after all.
Even if Antoine renamed it eliminating the original @Java_Social account (not sure, if I'd do it though, if a "timewaster" grabs it, you'll never ever get it again, I doubt, Twitter even thought about dispute resolutions there so far, except if let's say somebody reserved @BarackObama and only had 1 follower;-) you can't rename it into an account that is taken.
Werner