Third party apps do not update with the LTS. Though, they may have their own schedule of updates from the place you got them from, depending on whether they included their own repos in the installation.
Another issue, though it is quite rare, is that when the LTS is updated some of your third party apps may stop working. As I said, this is rare, but it can happen. I can only guess it is due to some systemic change in the main operating system, following the upgrade, which then makes it incompatible with the third party app that was installed.
When this happens, though, it is common for the third party app devs to bring out an upgraded version of the app and/or provide updates to the existing version which fix the problem.
Very rarely, though, this doesn’t happen and you can end up with a third party app that is irretrievably broken. In which case, you just have to deal with it.
There are ways that you can deal with such a rare eventuality. It involves the use of VM’s and, if you ever had that problem, come on here and I would be happy to explain.