Yes, the source is not citable by Wikipedia's standard, but it appears that Mulcahy is considered an established personality in the recreational mathematics community, and his source was private communication from the close associates of John Conway, which by itself is backed up by Colin Wright, an established personality on Hacker News. [0][1] So it's certain to say the information is true.
By the way, I once said that Twitter is now the center of gravity of the web these days, and someone didn't believe me and argued against it with some user statistics, which missed the point. This is another example on how Twitter is the center of gravity, it is, in the sense of its network effect - that it has a group of active and influential people, which makes it the place where the latest news and rumors break out. Not different from the early blogosphere, the Usenet, or even Hacker News posts about Silicon Valley.
By the way, I once said that Twitter is now the center of gravity of the web these days, and someone didn't believe me and argued against it with some user statistics, which missed the point. This is another example on how Twitter is the center of gravity, it is, in the sense of its network effect - that it has a group of active and influential people, which makes it the place where the latest news and rumors break out. Not different from the early blogosphere, the Usenet, or even Hacker News posts about Silicon Valley.
[0] https://news.ycombinator.com/item?id=22843577
[1] https://news.ycombinator.com/item?id=22844444