It looks like the URLs in the OP are no longer oneboxable (no opengraph tags on the site). But just noting for the record, this issue should have been resolved by
https://github.com/discourse/discourse/commit/f0a02525267e88986581be1f87c9e5608b9a4377
It looks like the URLs in the OP are no longer oneboxable (no opengraph tags on the site). But just noting for the record, this issue should have been resolved by
https://github.com/discourse/discourse/commit/f0a02525267e88986581be1f87c9e5608b9a4377