Just to clarify, that is how Ubuntu's LTS [Long Term Support] releases are intended to work. The 'point one' release fixes bugs in the initial release and keeps the same kernel. It winds up being the actual release that is supported 'Long Term'. Releases 'point two' and later get updated kernels...and potentially new bugs to go with new features.

I won't say that the End of Life illustration is easy to interpret, but it shows how Ubuntu releases work:

https://www.ubuntu.com/info/release-end-of-life