Just a quick update: mobile service confirmed that, as long as it triggers alerts for blind spot monitoring and lane keeping features, condensation on the interior surface of the camera cover glass is not normal. They replaced both b-pillar cameras and covers under warranty today. They also mentioned that Tesla engineers are looking for a long-term solution as the issue has started to come up on a lot of cars.
The tech basically said he expects it to happen again, at least over time; replacing the cover is a temporary solution until a better design is in place. According to him, engineering is actively working on a redesign that would provide a better seal between the top portion of the camera enclosure and the glass applique. The parts that were replaced are 1109253-90-F and 109255-90-F. Interestingly, the parts catalog already shows what I think are later revisions for both: 1109253-00-G and 1109255-00-G.
I have experienced this on both of my cameras and so I am curious as to the conclusion as well.