The first Ubuntu 24.04 LTS point release won't be released this week, as initially planned. Ubuntu developers had been aiming to get Ubuntu 24.04.1 LTS
24.04 was released in April, as usual. Here we're talking about 24.04.1, which could be seen as a "Service Pack" as it includes every patches released since then.
I think the "upgrade bugs" mentioned in the article are bugs happening when upgrading from previous LTS versions of Ubuntu, as usually the . 1 release is the first one to be suggested for upgrade to these installs.