This issue just came up on a new community I recently joined. Without bootstrap mode and little to read, engagement has been slow to pick up. One member started a topic because they were confused about receiving a PM email notification from staff and being unable to find the PM to reply. They are still TL0 and will be stuck there until there is enough to read so they can get up to TL1 and access their messages.
A corollary issue is that they are not able to just click a link in the email to access it directly and reply. They say they just got a blank page. I don’t know if this is related to another site setting change they’ve made or to trust level defaults.
Another funny side effect is that my own posts to meta to help educate that community about how all this works just got flagged! I presume that’s because I also am stuck at TL0 on that site. And hilarity ensues..