I didn't find the posts regarding Firejail. Perhaps they are old, and Firejail has improved since then. In any case, Firejail basically uses the same technology as Chromium does. So if Firejail is affected by these problems, Chromium is probably, too. However, the difference is that in Chromium only the renderer is sandboxed while with Firejail the broker (which has access to the file system) is sandboxed as well. Besides, there is a nodbus switch which is enabled in the chromium-common.profile and firefox-common.profile (perhaps this had not been available at the time of the writing of these tweets).